Doctor of Science, Osaka University

Thermoelectric devices

Electronic material (organic, Inorganic)

Solar cell (Photovoltaic devices)

Photoelectric conversion device

Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Electric/electronic material engineering

Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Electronic devices and equipment

Nanotechnology/Materials, Polymer materials

Nanotechnology/Materials, Organic functional materials

01 Apr. 2001 - 31 Mar. 2019
Kyushu Institute of Technology, Graduate School of Life Science and Systems Engineering, Professor

01 Apr. 1978 - 31 Mar. 2001
Toshiba Corporation, Research and Development Center, 退職時 研究主幹（部長）

Mar. 1983
Osaka University, 理学研究科

Mar. 1978
Osaka University, 理学研究科, 高分子化学

Exceeding 15% Performance with Energy Level Tuning in Tin-Based Perovskite Solar Cells
Liang Wang; Huan Bi; Jiaqi Liu; Yuyao Wei; Zheng Zhang; Mengmeng Chen; Ajay Kumar Baranwal; Gaurav Kapil; Takeshi Kitamura; Shuzhang Yang; Qingqing Miao; Qing Shen; Tingli Ma; Shuzi Hayase
ACS Energy Letters, American Chemical Society (ACS), 9, 12, 6238-6244, 05 Dec. 2024
Scientific journal

The Application of Metallic Sn in Sn-Based Perovskite Solar Cells
Liang Wang; Hong Zhang; Qing Shen; Shuzi Hayase
ChemNanoMat, 10, 10, Oct. 2024
Scientific journal

Enhanced Electron Transport in Heterojunction Sn-Perovskite Solar Cells Assisted by [6,6]-Phenyl-C61-butyric Acid Methyl Ester as a Dopant
Ajay Kumar Baranwal; Huan Bi; Gaurav Kapil; Takeshi Kitamura; Liang Wang; Jiaqi Liu; Qing Shen; Shuzi Hayase
ACS Energy Letters, 9, 8, 4119-4126, 09 Aug. 2024
Scientific journal

Double side passivation of phenylethyl ammonium iodide for all perovskite tandem solar cell with efficiency of 26.8%
Huan Bi; Jiaqi Liu; Liang Wang; Zheng Zhang; Gaurav Kapil; Shahrir Razey Sahamir; Ajay Kumar Baranwal; Yuyao Wei; Yongge Yang; Dandan Wang; Takeshi Kitamura; Hiroshi Segawa; Qing Shen; Shuzi Hayase
EcoEnergy, Wiley, 02 Jul. 2024, Abstract

All‐perovskite tandem solar cells are regarded as the next generation of devices capable of enhancing the solar energy utilization rate. Unlike single‐junction perovskite solar cells (PSCs), the efficacy of tandem cells is contingent upon the performance of both the top and bottom cells. In this study, we employed a simultaneous co‐modification strategy to incorporate phenylethylammonium iodide (PEAI) at both the top and bottom interfaces of the perovskite film, aiming to boost the top cell's performance. Both experimental and theoretical findings indicate that PEAI not only elevates the perovskite film quality through chemical interactions but also mitigates nonradiative recombination within the device. Consequently, the efficiency of the wide‐bandgap (1.77 eV) PSCs based on nickel oxide (NiO_x) attained a level of 16.5%. Simultaneously, the all‐perovskite tandem solar cells achieved an efficiency of 26.81% and demonstrated superior stability.
Scientific journal

Restraining Photocurrent Loss of Lead-Free Perovskite Solar Cells by Regulating Surficial Hydroxyl of Fluorine-Doped Tin Oxide
Jiaqi Liu; Huan Bi; Zheng Zhang; Yasuhiro Fujiwara; Yoshitaka Sanehira; Gaurav Kapil; Takeshi Kitamura; Shahrir Razey Sahamir; Ajay Kumar Baranwal; Liang Wang; Qing Shen; Shuzi Hayase
ACS Applied Energy Materials, 7, 11, 4779-4785, 10 Jun. 2024
Scientific journal

Direct measurement of electron affinity of carbazole-based self-assembled monolayer used as hole-selective layer in high-efficiency perovskite solar cells
Aruto Akatsuka; Makoto Miura; Gaurav Kapil; Shuzi Hayase; Hiroyuki Yoshida
Applied Physics Letters, AIP Publishing, 124, 24, 10 Jun. 2024, Carbazole-based self-assembled monolayers have received considerable attention as hole-selective layers (HSLs) in inverted perovskite solar cells. As an HSL, the electron-blocking capability is important and directly related to electron affinity (EA). Low-energy inverse photoelectron spectroscopy (LEIPS) is the most reliable method for EA measurement. However, the intense electron-impact-induced fluorescence from carbazole interferes with their measurement. By improving the photon detector, we were able to measure 2PACz and MeO-2PACz LEIPS spectra and determine their respective EAs of 1.72 and 1.48 eV. These small EA values ensure effective electron-blocking capability of HSLs regardless of the type of perovskite layer.
Scientific journal

Midgap states and energy alignment at interconnect are crucial for perovskite tandem solar cells
Gaurav Kapil; Yasuhiro Fujiwara; Huan Bi; Ajay Kumar Baranwal; Shahrir Razey Sahamir; Jiaqi Liu; Liang Wang; Daisuke Hirotani; Qing Shen; Hiroshi Segawa; Shuzi Hayase
Cell Reports Physical Science, Elsevier BV, 102060-102060, Jun. 2024
Scientific journal

Elucidating the Mechanisms of the Large Stokes Shift in Isolated and Coupled PbS Quantum Dots
Hua Li; Chao Ding; Naoki Oguri; Yuuya Makino; Dong Liu; Yao Guo; Yuyao Wei; Yusheng Li; Yongge Yang; Dandan Wang; Shikai Chen; Taizo Masuda; Shuzi Hayase; Tomah Sogabe; Qing Shen
Journal of Physical Chemistry C, 128, 21, 8732-8740, 30 May 2024
Scientific journal

Photoexcited Carrier Dynamics in Iodine-Doped CH3NH3PbBr3 Single Crystals
Dong Liu; Chao Ding; Yao Guo; Hua Li; Yusheng Li; Dandan Wang; Yongge Yang; Yuyao Wei; Shikai Chen; Guozheng Shi; Taro Toyoda; Dong Won Kang; Shuzi Hayase; Qing Shen
Journal of Physical Chemistry Letters, 15, 21, 5618-5624, 30 May 2024
Scientific journal

Stronger Coupling of Quantum Dots in Hole Transport Layer Through Intermediate Ligand Exchange to Enhance the Efficiency of PbS Quantum Dot Solar Cells
Yuyao Wei; Chao Ding; Guozheng Shi; Huan Bi; Yusheng Li; Hua Li; Dong Liu; Yongge Yang; Dandan Wang; Shikai Chen; Ruixiang Wang; Shuzi Hayase; Taizo Masuda; Qing Shen
Small Methods, Wiley, 12 Apr. 2024, Abstract

Nowadays, the extensively used lead sulfide (PbS) quantum dot (QD) hole transport layer (HTL) relies on layer‐by‐layer method to replace long chain oleic acid (OA) ligands with short 1,2‐ethanedithiol (EDT) ligands for preparation. However, the inevitable significant volume shrinkage caused by this traditional method will result in undesired cracks and disordered QD arrangement in the film, along with adverse increased defect density and inhomogeneous energy landscape. To solve the problem, a novel method for EDT passivated PbS QD (PbS‐EDT) HTL preparation using small‐sized benzoic acid (BA) as intermediate ligands is proposed in this work. BA is substituted for OA ligands in solution followed by ligand exchange with EDT layer by layer. With the new method, smoother PbS‐EDT films with more ordered and closer QD packing are gained. It is demonstrated stronger coupling between QDs and reduced defects in the QD HTL owing to the intermediate BA ligand exchange. As a result, the suppressed nonradiative recombination and enhanced carrier mobility are achieved, contributing to ≈20% growth in short circuit current density (J_sc) and a 23.4% higher power conversion efficiency (PCE) of 13.2%. This work provides a general framework for layer‐by‐layer QD film manufacturing optimization.
Scientific journal

Achieving High Efficiency and Enhanced Thermal Stability in Germanium-Encapsulated Tin–Lead Perovskite Solar Cells
Shahrir Razey Sahamir; Gaurav Kapil; Takeru Bessho; Hiroshi Segawa; Qing Shen; Shuzi Hayase
ACS Materials Letters, American Chemical Society (ACS), 6, 4, 1241-1246, 04 Mar. 2024
Scientific journal

Over 14% efficiency of highly reproducible Sn perovskite solar cell via defect passivation and morphology repairment
Zheng Zhang; Jiaqi Liu; Huan Bi; Liang Wang; Qing Shen; Shuzi Hayase
Chemical Engineering Journal, Elsevier BV, 483, 149345-149345, Mar. 2024
Scientific journal

Classifying the Role of Surface Ligands on the Passivation and Stability of Cs2NaInCl6 Double Perovskite Quantum Dots
Keita Tosa; Chao Ding; Shikai Chen; Shuzi Hayase; Qing Shen
Nanomaterials, MDPI AG, 14, 4, 376-376, 17 Feb. 2024, Cs2NaInCl6 double perovskites, which have excellent photoelectric conversion properties and are non-toxic and lead-free, have recently gained significant attention. In particular, double-perovskite quantum dots (QDs) are viewed as a promising material for optoelectronic device applications. Ligands such as oleic acid (OA) and oleylamine (OAm) are essential for the synthesis of perovskite QDs, but their specific roles in double-perovskite QDs remain unclear. In this study, we have investigated the binding of OA and OAm to Cs2NaInCl6 QDs through FTIR and NMR and their effects on the surface defect reduction and stability improvement for Cs2NaInCl6 QDs. We found that only OAm was bound to the QD surfaces while OA was not. The OAm has a significant effect on the photoluminescence quantum yield (PLQY) improvement by passivating the QD surface defects. The stability of the QDs was also evaluated, and it was observed that OA played a significant role in the stability of the QDs. Our findings provide valuable insights into the roles of ligands in influencing the photophysical properties and stability of lead-free double-perovskite QDs.
Scientific journal

Stable Inorganic Colloidal Tin and Tin–Lead Perovskite Nanocrystals with Ultralong Carrier Lifetime via Sn(IV) Control
Yusheng Li; Dandan Wang; Yongge Yang; Chao Ding; Yuyu Hu; Feng Liu; Yuyao Wei; Dong Liu; Hua Li; Guozheng Shi; Shikai Chen; Hongshi Li; Akihito Fuchimoto; Keita Tosa; Unno Hiroki; Shuzi Hayase; Huiyun Wei; Qing Shen
Journal of the American Chemical Society, American Chemical Society (ACS), 146, 5, 3094-3101, 25 Jan. 2024
Scientific journal

Deciphering the Atomic-Scale Structural Origin for Photoluminescence Quenching in Tin-Lead Alloyed Perovskite Nanocrystals
Dandan Wang; Yusheng Li; Yongge Yang; Yao Guo; Huiyun Wei; Feng Liu; Chao Ding; Yuyao Wei; Dong Liu; Hua Li; Guozheng Shi; Shikai Chen; Hongshi Li; Akihito Fuchimoto; Jing Xia; Shuzi Hayase; Qing Shen
ACS Nano, 2024
Scientific journal

Energetic disorder dominates optical properties and recombination dynamics in tin-lead perovskite nanocrystals
Dandan Wang; Yusheng Li; Yongge Yang; Chao Ding; Yuyao Wei; Dong Liu; Hua Li; Huan Bi; Shikai Chen; Sujun Ji; Boyu Zhang; Yao Guo; Huiyun Wei; Hongshi Li; Shuzi Hayase; Qing Shen
eScience, 2024
Scientific journal

Ternary Passivation for Enhanced Carrier Transport and Recombination Suppression in Highly Efficient Sn-Based Perovskite Solar Cells
Liang Wang; Qingqing Miao; Dandan Wang; Zheng Zhang; Mengmeng Chen; Huan Bi; Jiaqi Liu; Ajay Kumar Baranwal; Gaurav Kapil; Yoshitaka Sanehira; Takeshi Kitamura; Qing Shen; Tingli Ma; Shuzi Hayase
Small, 2024
Scientific journal

In Situ Room-Temperature Synthesis of All-Colloidal Quantum Dot CsPbBr₃–PbS Heterostructures
Yongge Yang; Dandan Wang; Yusheng Li; Jing Xia; Huiyun Wei; Chao Ding; Yuyu Hu; Yuyao Wei; Hua Li; Dong Liu; Guozheng Shi; Yaohong Zhang; Huan Bi; Shikai Chen; Hongshi Li; Xiang-Min Meng; Shuzi Hayase; Qing Shen
ACS Photonics, American Chemical Society (ACS), 10, 12, 4305-4314, 20 Nov. 2023
Scientific journal

Anchoring self-assembled monolayer at perovskite/hole collector interface for wide bandgap Sn-based solar cells with a record efficiency over 12%
SungWon Cho; Padmini Pandey; Saemon Yoon; Jun Ryu; Dong-Gun Lee; Qing Shen; Shuzi Hayase; Hochan Song; Hyosung Choi; Hyungju Ahn; Chang-Mok Oh; In-Wook Hwang; Jung Sang Cho; Dong-Won Kang
Surfaces and Interfaces, Elsevier BV, 42, 103478-103478, Nov. 2023
Scientific journal

Ferrocene Derivatives for Improving the Efficiency and Stability of MA‐Free Perovskite Solar Cells from the Perspective of Inhibiting Ion Migration and Releasing Film Stress
Huan Bi; Jiaqi Liu; Zheng Zhang; Liang Wang; Gaurav Kapil; Yuyao Wei; Ajay Kumar Baranwal; Shahrir Razey Sahamir; Yoshitaka Sanehira; Dandan Wang; Yongge Yang; Takeshi Kitamura; Raminta Beresneviciute; Saulius Grigalevicius; Qing Shen; Shuzi Hayase
Advanced Science, Wiley, 10, 35, 22 Oct. 2023, Abstract

Further improvement of the performance and stability of inverted perovskite solar cells (PSCs) is necessary for commercialization. Here, ferrocene derivative dibenzoylferrocene (DBzFe) is used as an additive to enhance the performance and stability of MA‐ and Br‐ free PSCs. The results show that the introduction of DBzFe not only passivates the defects in the film but also inhibits the ion migration in the film. The final device achieves a power conversion efficiency (PCE) of 23.53%, which is one of the highest efficiencies currently based on self‐assembled monolayers (SAMs). Moreover, it maintains more than 96.4% of the original efficiency when running continuously for 400 h at the maximum power point.
Scientific journal

All-Perovskite Tandem Solar Cells Approach 26.5% Efficiency by Employing Wide Bandgap Lead Perovskite Solar Cells with New Monomolecular Hole Transport Layer
Huan Bi; Jiaqi Liu; Zheng Zhang; Liang Wang; Raminta Beresneviciute; Daiva Tavgeniene; Gaurav Kapil; Chao Ding; Ajay Kumar Baranwal; Shahrir Razey Sahamir; Yoshitaka Sanehira; Hiroshi Segawa; Saulius Grigalevicius; Qing Shen; Shuzi Hayase
ACS Energy Letters, American Chemical Society (ACS), 8, 9, 3852-3859, 24 Aug. 2023
Scientific journal

Efficiency Enhancement of Wide Bandgap Lead Perovskite Solar Cells with PTAA Surface-Passivated with Monomolecular Layer from the Viewpoint of PTAA Band Bending
Huan Bi; Jiaqi Liu; Raminta Beresneviciute; Daiva Tavgeniene; Zheng Zhang; Liang Wang; Gaurav Kapil; Chao Ding; Shahrir Razey Sahamir; Yoshitaka Sanehira; Ajay Kumar Baranwal; Takeshi Kitamura; Dandan Wang; Yuyao Wei; Yongge Yang; Dong-Won Kang; Saulius Grigalevicius; Qing Shen; Shuzi Hayase
ACS Applied Materials & Interfaces, 22 Aug. 2023
Scientific journal

14.31 % Power Conversion Efficiency of Sn‐Based Perovskite Solar Cells via Efficient Reduction of Sn4+
Liang Wang; Qingqing Miao; Dandan Wang; Mengmeng Chen; Huan Bi; Jiaqi Liu; Ajay Kumar Baranwal; Gaurav Kapil; Yoshitaka Sanehira; Takeshi Kitamura; Tingli Ma; Zheng Zhang; Qing Shen; Shuzi Hayase
Angewandte Chemie, 14 Aug. 2023
Scientific journal

Enhancement of Efficiency and Stability for Tin Halide Perovskite Solar Cells by Using Improved Doping Method
Zheng Zhang; Liang Wang; Huan Bi; Ajay Kumar Baranwal; Gaurav Kapil; Yoshitaka Sanehira; Jiaqi Liu; Dong Liu; Qing Shen; Shuzi Hayase
Advanced Optical Materials, Wiley, 12, 2, 13 Aug. 2023, Abstract

In recent years, tin halide perovskite solar cells (PKSCs) have emerged as a promising alternative to lead‐PKSCs. However, due to defects such as Sn⁴⁺ and iodide vacancies, their efficiency is lower than lead‐PKSCs. To address this issue, various strategies are proposed to improve the quality of perovskite, including copper iodide (CuI) doping. Unfortunately, the conventional solvent composition of DMF:DMSO = 4:1 has limited the solubility of CuI, resulting in inconsistent results and limited efficiency improvements. However, this research proposed a preprocessing method of CuI to decrease the defects and improve the perovskite layer's morphology. As a result, the efficiency of tin‐PKSCs with both P‐I‐N and hole transport layer (HTL) free structures is enhanced, increasing from 9.8% to 13.1% and 9.4% to 10.5%, respectively. Moreover, the doped tin‐PKSCs have exhibited better stability, retaining 75% of their initial power conversion efficiency (PCE) after being stored in a glovebox for 102 days.
Scientific journal

Sn Perovskite Solar Cells with Tin Oxide Nanoparticle Layer as Hole Transport Layer
Takeshi Kitamura; Liang Wang; Zheng Zhang; Ajay Kumar Baranwal; Gaurav Kapil; Shahrir Razey Sahamir; Yoshitaka Sanehira; Huan Bi; Tingli Ma; Qing Shen; Shuzi Hayase
ACS Energy Letters, 11 Aug. 2023
Scientific journal

How to minimize voltage and fill factor losses to achieve over 20% efficiency lead chalcogenide quantum dot solar cells: Strategies expected through numerical simulation
Dandan Wang; Yusheng Li; Yongge Yang; Shuzi Hayase; Haifeng Wu; Ruixiang Wang; Chao Ding; Qing Shen
Applied Energy, Elsevier BV, 341, 121124-121124, Jul. 2023
Scientific journal

Optimization of Device Parameters for Back Contact Transparent Conductive Oxide Less Dye Sensitized Solar Cells Fabrication
Md Zaman Molla; Ajay Kumar Baranwal; Shuzi Hayase; Shyam S. Pandey
Physica Status Solidi-A, 20 Jun. 2023, Peer-reviwed
Scientific journal, English

Enhanced Hot-Phonon Bottleneck Effect on Slowing Hot Carrier Cooling in Metal Halide Perovskite Quantum Dots With Alloyed A-Site.
Hua Li; Qing Wang; Yusuke Oteki; Chao Ding; Dong Liu; Yao Guo; Yusheng Li; Yuyao Wei; Dandan Wang; Yongge Yang; Taizo Masuda; Mengmeng Chen; Zheng Zhang; Tomah Sogabe; Shuzi Hayase; Yoshitaka Okada; Satoshi Iikubo; Qing Shen
Advanced materials (Deerfield Beach, Fla.), e2301834, 13 Jun. 2023, True, A deep understanding of the effect of the A-site cation cross-exchange on the hot-carrier relaxation dynamics in perovskite quantum dots (PQDs) has profound implications on the further development of disruptive photovoltaic technologies. In this study, we investigated the hot carrier cooling kinetics of pure FAPbI3 , MAPbI3 , CsPbI3 and alloyed FA0.5 MA0.5 PbI3 , FA0.5 Cs0.5 PbI3 , and MA0.5 Cs0.5 PbI3 QDs using ultrafast transient absorption (TA) spectroscopy. The lifetimes of the initial fast cooling stage (<1 ps) of all the organic cation-containing PQDs were shorter than those of the CsPbI3 QDs, as verified by the electron-phonon coupling strength extracted from the temperature-dependent photoluminescence spectra. The lifetimes of the slow cooling stage of the alloyed PQDs were longer under illumination greater than 1 sun, which was ascribed to the introduction of co-vibrational optical phonon modes in the alloyed PQDs. This facilitated efficient acoustic phonon upconversion and enhanced the hot-phonon bottleneck effect, as demonstrated by first-principles calculations. This article is protected by copyright. All rights reserved.
Scientific journal, English

Low-Temperature Growth of ZnMgO Thin Films by Atmospheric Spin-Coating Using Diethylzinc Solution
Kenji Yoshino; Himeka Tominaga; Yuta Komaki; Masato Imai; Tomohiro Higashi; Takashi Minemoto; Qing Shen; Shuzi Hayase
Journal of Electronic Materials, Springer Science and Business Media LLC, 12 May 2023
Scientific journal

Perovskite Solar Cells Consisting of PTAA Modified with Monomolecular Layer and Application to All‐Perovskite Tandem Solar Cells with Efficiency over 25%
Huan Bi; Yasuhiro Fujiwara; Gaurav Kapil; Daiva Tavgeniene; Zheng Zhang; Liang Wang; Chao Ding; Shahrir Razey Sahamir; Ajay Kumar Baranwal; Yoshitaka Sanehira; Kitamura Takeshi; Guozheng Shi; Takeru Bessho; Hiroshi Segawa; Saulius Grigalevicius; Qing Shen; Shuzi Hayase
Advanced Functional Materials, Wiley, 33, 32, 26 Apr. 2023, Abstract

This study is on the enhancement of the efficiency of wide bandgap (FA_0.8Cs_0.2PbI_1.8Br_1.2) perovskite solar cells (PSCs) used as the top layer of the perovskite/perovskite tandem solar cell. Poly[bis(4‐phenyl) (2,4,6‐trimethylphenyl) amine] (PTAA) and the monomolecular layer called SAM layer are effective hole collection layers for APbI₃ PSCs. However, these hole transport layers (HTL) do not give high efficiencies for the wide bandgap FA_0.8Cs_0.2PbI_1.8Br_1.2 PSCs. It is found that the surface‐modified PTAA by monomolecular layer (MNL) improves the efficiency of PSCs. The improved efficiency is explained by the improved FA_0.8Cs_0.2PbI_1.8Br_1.2 film quality, decreased film distortion (low lattice disordering) and low density of the charge recombination site, and improves carrier collection by the surface modified PTAA layer. In addition, the relationship between the length of the alkyl group linking the anchor group and the carbazole group is also discussed. Finally, the wide bandgap lead PSCs (E_g = 1.77 eV) fabricated on the PTAA/monomolecular bilayer give a higher power conversion efficiency of 16.57%. Meanwhile, all‐perovskite tandem solar cells with over 25% efficiency are reported by using the PTAA/monomolecular substrate.
Scientific journal

A multifunctional additive strategy to stabilize the precursor solution and passivate film defects for MA-free perovskite solar cells with an efficiency of 22.75%
Huan Bi; Mengna Guo; Chao Ding; Shuzi Hayase; Qing Shen; Gaoyi Han; Wenjing Hou
Materials Today Energy, Elsevier BV, 33, 101269-101269, Apr. 2023
Scientific journal

Reduced interfacial recombination losses and lead leakage in lead-based perovskite solar cells using 2D/3D perovskite engineering
Huan Bi; Yao Guo; Mengna Guo; Chao Ding; Shuzi Hayase; Hanjun Zou; Qing Shen; Gaoyi Han; Wenjing Hou
Journal of Power Sources, Elsevier BV, 563, 232825-232825, Apr. 2023
Scientific journal

Efficient Charge Transfer in MAPbI₃ QDs/TiO₂ Heterojunctions for High-Performance Solar Cells
Hua Li; Chao Ding; Dong Liu; Shota Yajima; Kei Takahashi; Shuzi Hayase; Qing Shen
Nanomaterials, Apr. 2023
Scientific journal

Pb-free perovskite solar cells composed of Sn/Ge(1:1) alloyed perovskite layer prepared by spin-coating
Huan Bi; Mengmeng Chen; Liang Wang; Zheng Zhang; Chao Ding; Gaurav Kapil; Shahrir Razey Sahamir; Yoshitaka Sanehira; Ajay Kumar Baranwal; Takeshi Kitamura; Guozheng Shi; Qing Shen; Shuzi Hayase
Applied Physics Express, 01 Mar. 2023
Scientific journal

Simultaneous Characterization of Optical, Electronic, and Thermal Properties of Perovskite Single Crystals Using a Photoacoustic Technique
Dong Liu; Hua Li; Yusheng Li; Taro Toyoda; Koji Miyazaki; Shuzi Hayase; Chao Ding; Qing Shen
ACS Photonics, American Chemical Society (ACS), 10, 1, 265-273, 06 Jan. 2023
Scientific journal

Cylindrical transparent conductive oxide-free dye-sensitized solar cells with treated flat titanium sheet
Azwar Hayat; Ajay Kumar Baranwal; Masaki Nakamura; Fujisawa Shigeki; Shyam S. Pandey; Shuzi Hayase
Journal of Phonics for Energy (SPIE), 12, 4, 045502, 02 Dec. 2022, Peer-reviwed
Scientific journal, English

SnOx as Bottom Hole Extraction Layer and Top In Situ Protection Layer Yields over 14% Efficiency in Sn-Based Perovskite Solar Cells
Liang Wang; Mengmeng Chen; Shuzhang Yang; Namiki Uezono; Qingqing Miao; Gaurav Kapil; Ajay Kumar Baranwal; Yoshitaka Sanehira; Dandan Wang; Dong Liu; Tingli Ma; Kenichi Ozawa; Takeaki Sakurai; Zheng Zhang; Qing Shen; Shuzi Hayase
ACS ENERGY LETTERS, 7, 10, 3703-3708, Oct. 2022
Scientific journal, English

Sequential Passivation for Lead-Free Tin Perovskite Solar Cells with High Efficiency
Zheng Zhang; Muhammad Akmal Kamarudin; Ajay Kumar Baranwal; Gaurav Kapil; Shahrir Razey Sahamir; Yoshitaka Sanehira; Mengmeng Chen; Liang Wang; Qing Shen; Shuzi Hayase
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 61, 42, Oct. 2022
Scientific journal, English

Efficient Exciton Dislocation and Ultrafast Charge Extraction in CsPbI₃ Perovskite Quantum Dots by Using Fullerene Derivative as Semiconductor Ligand
Yusheng Li; Dandan Wang; Shuzi Hayase; Yongge Yang; Chao Ding; Qing Shen
Nanomaterials, Sep. 2022
Scientific journal

Unveiling the Role of the Metal Oxide/Sn Perovskite Interface Leading to Low Efficiency of Sn-Perovskite Solar Cells but Providing High Thermoelectric Properties
Ajay Kumar Baranwal; Shrikant Saini; Yoshitaka Sanehira; Gaurav Kapil; Muhammad Akmal Kamarudin; Chao Ding; Shahrir Razey Sahamir; Tomohide Yabuki; Satoshi Iikubo; Qing Shen; Koji Miyazaki; Shuzi Hayase
ACS Applied Energy Materials, 5, 8, 9750-9758, 22 Aug. 2022
Scientific journal

Indent-Free Vapor-Assisted Surface Passivation Strategy toward Tin Halide Perovskite Solar Cells
Zheng Zhang; Muhammad Akmal Kamarudin; Ajay Kumar Baranwal; Liang Wang; Gaurav Kapil; Shahrir Razey Sahamir; Yoshitaka Sanehira; Mengmeng Chen; Qing Shen; Shuzi Hayase
ACS Applied Materials and Interfaces, 14, 31, 36200-36208, 10 Aug. 2022
Scientific journal

Enhanced efficiency and stability in Sn-based perovskite solar cells by trimethylsilyl halide surface passivation
Zheng Zhang; Liang Wang; Ajay Kumar Baranwal; Shahrir Razey Sahamir; Gaurav Kapil; Yoshitaka Sanehira; Muhammad Akmal Kamarudin; Kohei Nishimura; Chao Ding; Dong Liu; Yusheng Li; Hua Li; Mengmeng Chen; Qing Shen; Teresa S. Ripolles; Juan Bisquert; Shuzi Hayase
JOURNAL OF ENERGY CHEMISTRY, 71, 604-611, Aug. 2022
Scientific journal, English

Unraveling the Organic and Inorganic Passivation Mechanism of ZnO Nanowires for Construction of Efficient Bulk Heterojunction Quantum Dot Solar Cells
Yuyao Wei; Mako Nakamura; Chao Ding; Dong Liu; Hua Li; Yusheng Li; Yongge Yang; Dandan Wang; Ruixiang Wang; Shuzi Hayase; Taizo Masuda; Qing Shen
ACS APPLIED MATERIALS & INTERFACES, Jul. 2022
Scientific journal, English

Influence of charge transport layer on the crystallinity and charge extraction of pure tin-based halide perovskite film
Yaohong Zhang; Muhammad Akmal Kamarudin; Qiao Li; Chao Ding; Yong Zhou; Yingfang Yao; Zhigang Zou; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Shuzi Hayase; Qing Shen
JOURNAL OF ENERGY CHEMISTRY, 69, 612-615, Jun. 2022
Scientific journal, English

Use of anti-solvent to enhance thermoelectric response of hybrid halide perovskite thin films
Shrikant Saini; Izuki Matsumoto; Sakura Kishishita; Ajay Kumar Baranwal; Tomohide Yabuki; Shuzi Hayase; Koji Miyazaki
Japanese Journal of Applied Physics, 61, SE, 01 Jun. 2022
Scientific journal

High performance wide bandgap Lead-free perovskite solar cells by monolayer engineering
Mengmeng Chen; Gaurav Kapil; Liang Wang; Shahrir Razey Sahamir; Ajay K. Baranwal; Kohei Nishimura; Yoshitaka Sanehira; Zheng Zhang; Muhammad Akmal Kamarudin; Qing Shen; Shuzi Hayase
Chemical Engineering Journal, 436, 15 May 2022
Scientific journal

Enhancing the Electronic Properties and Stability of High-Efficiency Tin-Lead Mixed Halide Perovskite Solar Cells via Doping Engineering.
Shahrir Razey Sahamir; Muhammad Akmal Kamarudin; Teresa S Ripolles; Ajay Kumar Baranwal; Gaurav Kapil; Qing Shen; Hiroshi Segawa; Juan Bisquert; Shuzi Hayase
The journal of physical chemistry letters, 13, 13, 3130-3137, 07 Apr. 2022, True, Overcoming Voc loss to increase the efficiency of perovskite solar cells (PSCs) has been aggressively studied. In this work, we introduce and compare rubidium iodide (RbI) and potassium iodide (KI) alkali metal halides (AMHs) as dopants in a tin-lead (SnPb)-based perovskite system to improve the performance of PSCs by enhancing their Voc. Improvement in terms of surface morphology, crystallinity, charge transfer, and carrier transport in the SnPb perovskites was observed with the addition of AMH dopants. Significant power conversion efficiency improvement has been achieved with the incorporation of either dopant, and the highest efficiency was 21.04% in SnPb mixed halide PSCs when the RbI dopant was employed. In conclusion, we can outline the enhancement strategy that yields a remarkable efficiency of >20% with a smaller Voc loss and improved storage, light, and thermal stability in SnPb PSCs via doping engineering.
Scientific journal, English

Relationship between Carrier Density and Precursor Solution Stirring for Lead-Free Tin Halide Perovskite Solar Cells Performance
Ajay Kumar Baranwal; Kohei Nishimura; Dong Liu; Muhammad Akmal Kamarudin; Gaurav Kapil; Shrikant Saini; Tomohide Yabuki; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Koji Miyazaki; Qing Shen; Shuzi Hayase
ACS Applied Energy Materials, 5, 4, 4002-4007, Apr. 2022
Scientific journal

Tin-Lead Perovskite Solar Cells Fabricated on Hole Selective Monolayers
Gaurav Kapil; Takeru Bessho; Yoshitaka Sanehira; Shahrir R. Sahamir; Mengmeng Chen; Ajay Kumar Baranwal; Dong Liu; Yuya Sono; Daisuke Hirotani; Daishiro Nomura; Kohei Nishimura; Muhammad Akmal Kamarudin; Qing Shen; Hiroshi Segawa; Shuzi Hayase
ACS Energy Letters, 7, 3, 966-974, 11 Mar. 2022
Scientific journal

Large synergy effects of doping, a site substitution, and surface passivation in wide bandgap Pb-free ASnI2Br perovskite solar cells on efficiency and stability enhancement
Mengmeng Chen; Gaurav Kapil; Yusheng Li; Muhammad Akmal Kamarudin; Ajay K. Baranwal; Kohei Nishimura; Shahrir Razey Sahamir; Yoshitaka Sanehira; Hua Li; Chao Ding; Zheng Zhang; Qing Shen; Shuzi Hayase
Journal of Power Sources, 520, 01 Feb. 2022
Scientific journal

Electronic structure and thermal conductance of the MASnI3/Bi2Te3 interface: a first-principles study.
Masayuki Morimoto; Shoya Kawano; Shotaro Miyamoto; Koji Miyazaki; Shuzi Hayase; Satoshi Iikubo
Scientific reports, 12, 1, 217-217, 07 Jan. 2022, True, To develop high-performance thermoelectric devices that can be created using printing technology, the interface of a composite material composed of MASnI3 and Bi2Te3, which individually show excellent thermoelectric performance, was studied based on first-principles calculations. The structural stability, electronic state, and interfacial thermal conductance of the interface between Bi2Te3 and MASnI3 were evaluated. Among the interface structure models, we found stable interface structures and revealed their specific electronic states. Around the Fermi energy, the interface structures with TeII and Bi terminations exhibited interface levels attributed to the overlapping electron densities for Bi2Te3 and MASnI3 at the interface. Calculation of the interfacial thermal conductance using the diffuse mismatch model suggested that construction of the interface between Bi2Te3 and MASnI3 could reduce the thermal conductivity. The obtained value was similar to the experimental value for the inorganic/organic interface.
Scientific journal, English

Unravelling the bottleneck of phosphonic acid anchoring groups aiming toward enhancing the stability and efficiency of mesoscopic solar cells
Ajendra Kumar Vats; Pritha Roy; Linjun Tang; Shuzi Hayase; Shyam S. Pandey
Frontiers of Chemical Science and Engineering, Springer Science and Business Media LLC, 26 Nov. 2021
Scientific journal

Large Grain Growth and Energy Alignment Optimization by Diethylammonium Iodide Substitution at A Site in Lead-Free Tin Halide Perovskite Solar Cells
Zheng Zhang; Ajay Kumar Baranwal; Shahrir Razey Sahamir; Gaurav Kapil; Yoshitaka Sanehira; Mengmeng Chen; Kohei Nishimura; Chao Ding; Dong Liu; Hua Li; Yusheng Li; Muhammad Akmal Kamarudin; Qing Shen; Teresa S. Ripolles; Juan Bisquert; Shuzi Hayase
SOLAR RRL, 5, 11, Nov. 2021
Scientific journal, English

Computational molecular design of NIR dyes with varying anchoring groups for improving the efficiency and stability of dye-sensitized solar cells
Pandey SHYAM; Ajendra Kumar Vats; Linjun Tang; Shuzi Hayase
Japanese Journal of Applied Physics, 61, SB, SB1021(1)-SB1021(11), 21 Sep. 2021, Peer-reviwed
Scientific journal, English

Preparation of nanocomposites of PbS quantum dots dispersed in MAPbI3matrix from precursor solution of Pb xanthate
Daisuke Hirotani; Kohei Nishimura; Yaohong Zhang; Qing Shen; Shuzi Hayase
Advances in Natural Sciences: Nanoscience and Nanotechnology, IOP Publishing Ltd, 12, 3, 01 Sep. 2021
Scientific journal, English

Tin-Lead Perovskite Fabricated via Ethylenediamine Interlayer Guides to the Solar Cell Efficiency of 21.74%
Gaurav Kapil; Takeru Bessho; Takatoshi Maekawa; Ajay Kumar Baranwal; Yaohong Zhang; Muhammad Akmal Kamarudin; Daisuke Hirotani; Qing Shen; Hiroshi Segawa; Shuzi Hayase
Advanced Energy Materials, 11, 25, 08 Jul. 2021
Scientific journal

Study of open circuit voltage loss mechanism in perovskite solar cells
Yulu He; Imane Abdellaoui; M. Abdel-Shakour; Towhid Hossain Chowdhury; Muhammad Akmal Kamarudin; Ana Flávia Nogueira; Qing Shen; Shuzi Hayase; Ashraful Islam; Takeaki Sakurai
Japanese Journal of Applied Physics, IOP Publishing Ltd, 60, 01 May 2021
Scientific journal, English

Ultra-Halide-Rich Synthesis of Stable Pure Tin-Based Halide Perovskite Quantum Dots: Implications for Photovoltaics
Feng Liu; Junke Jiang; Taro Toyoda; Muhammad Akmal Kamarudin; Shuzi Hayase; Ruixiang Wang; Shuxia Tao; Qing Shen
ACS Applied Nano Materials, American Chemical Society, 4, 4, 3958-3968, 23 Apr. 2021
Scientific journal, English

Impact of Auger recombination on performance limitation of perovskite solar cell
Jakapan Chantana; Yu Kawano; Takahito Nishimura; Abdurashid Mavlonov; Qing Shen; Kenji Yoshino; Satoshi Iikubo; Shuzi Hayase; Takashi Minemoto
Solar Energy, Elsevier Ltd, 217, 342-353, 15 Mar. 2021
Scientific journal, English

Surface structure of quasi-2D perovskite PEA2mMAn−2mPbnI3n (n ≫ m)
Abduheber Mirzehmet; Tomoki Ohtsuka; Syed A. Abd. Rahman; Takumi Aihara; Muhammad Akmal Kamarudin; Shahrir Razey Sahamir; Shuzi Hayase; Tomoki Yuyama; Peter Krüger; Hiroyuki Yoshida
Applied Physics Express, IOP Publishing, 14, 3, 031006-031006, 01 Mar. 2021, Peer-reviwed
Scientific journal

Relationship between perovsktie solar cell efficiency and lattice disordering
Daisuke Hirotani; Kohei Nishimura; Kengo Hamada; Muhammad Akmal Kamarudin; Satoshi Iikubo; Qing Shen; Taro Toyoda; Shuzi Hayase
Japanese Journal of Applied Physics, IOP Publishing, 60, 3, 035001-035001, 15 Feb. 2021, Abstract

Multi-cations lead perovskite solar cells have shown higher performance than single-cation perovskite solar cells. This compositional engineering of perovskite material retains the optimum tolerance factor while allowing the tuning of the band gap in addition to the enhanced stability of cubic phase perovskite. However, no in-depth explanation has been provided on the relationship between crystal structure of the perovskite and the solar cell efficiency. In this report, we investigate the effect of lattice disordering of FA_xMA_1−xPbI₃ perovskite on the tolerance factor and solar cell efficiency. The lattice disordering estimated using Williamson–Hall plot of XRD analysis revealed that the disordering is lowest when x = 0.2 and highest when x = 1.0. Correspondingly, x = 0.2 showed the highest solar cell performance and long carrier lifetime Our results show that the disordering in α phase of FA_xMA_1−xPbI₃ layer causes lattice deformation which affects the carrier lifetime and solar cell efficiency, instead of the defects on constituent elements.
Scientific journal

Effect of impurity elements on the structural stability and electronic state in tin iodide perovskite
J. Yamasaki; S. Iikubo; K. Yamamoto; K. Tanaka; Y. Ogomi; S. Hayase
Journal of Solid State Chemistry, Academic Press Inc., 293, 01 Jan. 2021
Scientific journal, English

Inverted CsPbI2Br perovskite solar cells with enhanced efficiency and stability in ambient atmosphere via formamidinium incorporation
Mengmeng Chen; Shahrir R. Sahamir; Gaurav Kapil; Ajay K. Baranwal; Muhammad Akmal Kamarudin; Yaohong Zhang; Kohei Nishimura; Chao Ding; Dong Liu; Daisuke Hirotani; Qing Shen; Shuzi Hayase
Solar Energy Materials and Solar Cells, 218, Dec. 2020
Scientific journal

Inorganic narrow bandgap CsPb0.4Sn0.6I2.4Br0.6 perovskite solar cells with exceptional efficiency
Seojun Lee; Janghyuk Moon; Jun Ryu; Bhaskar Parida; Saemon Yoon; Dong-Gun Lee; Jung Sang Cho; Shuzi Hayase; Dong-Won Kang
Nano Energy, Elsevier Ltd, 77, 01 Nov. 2020
Scientific journal, English

Passivation Strategy of Reducing Both Electron and Hole Trap States for Achieving High-Efficiency PbS Quantum-Dot Solar Cells with Power Conversion Efficiency over 12%
Chao Ding; Feng Liu; Yaohong Zhang; Shuzi Hayase; Taizo Masuda; Ruixiang Wang; Yong Zhou; Yingfang Yao; Zhigang Zou; Qing Shen
ACS Energy Letters, American Chemical Society, 5, 10, 3224-3236, 09 Oct. 2020
Scientific journal, English

Effect of electrolyte for back contact transparent conducting oxide-less dye-sensitized solar cells: Iodine versus cobalt
Md Zaman Molla; Ajay K. Baranwal; Shuzi Hayase; Shyam S. Pandey
Journal of Photonics for Energy, 10, 4, 01 Oct. 2020
Scientific journal

Boosting the Efficiency of Low-Cost T-C-O-Less Dye-Sensitized Solar Cells Employing Nanoparticle Spacers and Cobalt Complex Redox Shuttle
Md Zaman Molla; Ajay Kumar Baranwal; Shuzi Hayase; Shyam S. Pandey
ACS Applied Electronic Materials, 2, 9, 2721-2729, 22 Sep. 2020
Scientific journal

Parametric optimization of back-contact T-C-O-free dye-sensitized solar cells employing indoline and porphyrin sensitizer based on cobalt redox electrolyte
Md Zaman Molla; Ajay Kumar Baranwal; Gaurav Kapil; Shuzi Hayase; Shyam S. Pandey
Solar Energy, 208, 411-418, 15 Sep. 2020
Scientific journal

Stability Improvement of Perovskite Solar Cells by Adding Sb-Xanthate to Precursor Solution
Kyung-Su Nam; Suvratha Krishnamurthy; Shen Qing; Taro Toyoda; Kenji Yoshino; Takashi Minemoto; Tingli Ma; Shyam Pandey; Shuzi Hayase
Physica Status Solidi (A) Applications and Materials Science, Wiley-VCH Verlag, 217, 18, 01 Sep. 2020
Scientific journal, English

A New Strategy for Increasing the Efficiency of Inverted Perovskite Solar Cells to More than 21%: High-Humidity Induced Self-Passivation of Perovskite Films
Fan Zhang; Qingxun Huang; Jun Song; Shuzi Hayase; Junle Qu; Qing Shen
SOLAR RRL, 4, 9, Sep. 2020
Scientific journal, English

Synthesis of Sb(V) complexes with pyridyl cations and application for lead-free perovskite solar cells
Zhenhua Xu; Chu Zhang; Fengyang Yu; Yusuke Kamata; Shuzi Hayase; Tingli Ma
Chemistry Letters, Chemical Society of Japan, 49, 8, 944-946, 05 Aug. 2020
Scientific journal, English

Interdiffusion Stomatal Movement in Efficient Multiple-Cation-Based Perovskite Solar Cells.
Cong Li; Zhinan Zhu; Bingqiang Niu; Fu Yang; Xinpeng Chen; Yingke Ren; Peng Zhong; Shuzi Hayase; Tianhong Cui; Rusen Yang
ACS applied materials & interfaces, 12, 31, 35105-35112, 05 Aug. 2020, True, The composition and crystallization process are essential for high-quality perovskite films. Cesium (Cs) and methylammonium chlorine (MACl) were found to affect the crystallization kinetics of perovskite, and the performance and stability of corresponding devices were greatly improved. We adopted an ion exchange method to remove MACl vapor and add Cs to form a multiple-cation-based perovskite film. With the increase of annealing time, Cl- from cesium chloride (CsCl) and MA from methylammonium bromide (MABr) formed gradually MACl vapor, and the porosity of surface morphology improved accordingly. The highly crystallized and compact CsyMAx - yFA1 - xPbI3 - xBrx perovskite film with different compositions was eventually obtained. The effects of the amount of MABr on the property of perovskite films and on the performance of the corresponding perovskite solar cells (PerSCs) were systematically studied. The PerSCs derived from 12 mg of MABr exhibit the best photovoltaic performance with a power conversion efficiency of 21.57% under 1 sun illumination.
Scientific journal, English

Lead-free tin-halide perovskite solar cells with 13% efficiency
Kohei Nishimura; Muhammad Akmal Kamarudin; Daisuke Hirotani; Kengo Hamada; Qing Shen; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Shuzi Hayase
Nano Energy, Elsevier {BV}, 74, 104858-104858, Aug. 2020, Peer-reviwed
Scientific journal

Cesium Acetate-Induced Interfacial Compositional Change and Graded Band Level in MAPbI3 Perovskite Solar Cells.
Ajay Kumar Jena; Ayumi Ishii; Zhanglin Guo; Muhammad Akmal Kamarudin; Shuzi Hayase; Tsutomu Miyasaka
ACS applied materials & interfaces, 12, 30, 33631-33637, 29 Jul. 2020, True, Compositional engineering and interfacial modifications have played pivotal roles in the accomplishment of high-efficiency perovskite solar cells (PSCs). Different interfaces in the PSCs influence the performance remarkably either by altering the crystallization of the active material or shifting the energy levels or improving the electrical contact. This work reports how a thin layer of cesium acetate on the TiO2 electron transport layer (ETL) induces generation of a PbI2-rich methylammonium lead iodide (MAPbI3) composition at the ETL/MAPbI3 interface, which downshifts the conduction band level of MAPbI3 to create an energy level gradient favorable for carrier collection, resulting in higher photocurrent, fill factor, and overall power conversion efficiency.
Scientific journal, English

Interface engineering with a novel n-type small organic molecule for efficient inverted perovskite solar cells
Helin Wang; Fu Yang; Ning Li; Jun Song; Junle Qu; Shuzi Hayase; Wai-Yeung Wong
Chemical Engineering Journal, Elsevier B.V., 392, 15 Jul. 2020
Scientific journal, English

The effect of p/n junction position on perovskite solar cell efficiency by changing polarity of the perovskite layer
Daisuke Hirotani; Yuta Maeda; Muhammad Akmal Kamarudin; Shen Qing; Taro Toyoda; Shuzi Hayase
Japanese Journal of Applied Physics, Institute of Physics Publishing, 59, 6, 01 Jul. 2020
Scientific journal, English

Unileg thermoelectric module comprised by coated halide-perovskite thin film
Shrikant Saini; Ajay Kumar Baranwal; Tomohide Yabuki; Shuzi Hayase; Koji Miyazaki
Journal of Heat Transfer, 142, 7, Jul. 2020
Scientific journal

In-Depth Exploration of the Charge Dynamics in Surface-Passivated ZnO Nanowires
Yaohong Zhang; Shuhei Ozu; Guohua Wu; Chao Ding; Feng Liu; Dong Liu; Takashi Minemoto; Taizo Masuda; Shuzi Hayase; Taro Toyoda; Qing Shen
JOURNAL OF PHYSICAL CHEMISTRY C, 124, 29, 15812-15817, Jul. 2020
Scientific journal, English

Efficient Surface Passivation and Electron Transport Enable Low Temperature-Processed Inverted Perovskite Solar Cells with Efficiency over 20%
Helin Wang; Fu Yang; Ning Li; Muhammad Akmal Kamarudin; Junle Qu; Jun Song; Shuzi Hayase; Christoph J. Brabec
ACS Sustainable Chemistry & Engineering, American Chemical Society ({ACS}), 15 Jun. 2020, Peer-reviwed
Scientific journal

Pb free perovskite solar cells with over 13 % efficiency-Direction to high efficiency-Pb free solar cells
Kohei Nishimura; Muhammad Akmal Kamarudin; Daisuke Hirotani; Shen Qing; Takashi Minemoto; Satoshi Iikubo; Kengo Yoshino; Shuzi Hayase
Conference Record of the IEEE Photovoltaic Specialists Conference, Institute of Electrical and Electronics Engineers Inc., 2020-, 0661-0663, 14 Jun. 2020
International conference proceedings, English

VOC Over 1.4 V for Amorphous Tin-Oxide-Based Dopant-Free CsPbI2Br Perovskite Solar Cells.
Zhanglin Guo; Ajay Kumar Jena; Izuru Takei; Gyu Min Kim; Muhammad Akmal Kamarudin; Yoshitaka Sanehira; Ayumi Ishii; Youhei Numata; Shuzi Hayase; Tsutomu Miyasaka
Journal of the American Chemical Society, 142, 21, 9725-9734, 27 May 2020, True, CsPbI2Br perovskite solar cells have attracted much attention because of the rapid development in their efficiency and their great potential as a top cell of tandem solar cells. However, the VOC outputs observed so far in most cases are far from that desired for a top cell. Up to now, with various kinds of treatments, the reported champion VOC is only 1.32 V, with a VOC deficit of 0.60 V. In this work, we found that aging of the SnCl2 precursor solution for the electron-transporting layer can promote the VOC of CsPbI2Br solar cells by employing a dopant-free-polymer hole transport material (HTM) over 1.40 V and efficiency over 15.5% with high reproducibility. With the champion VOC of 1.43 V, the VOC deficit was reduced to <0.50 V, which is achieved for the first time. This simple technique of SnCl2 solution aging forms a uniform and smooth amorphous SnOx film with pure Sn4+, elevates the conduction band of SnOx, and reduces the interfacial gaps and the trap state density of the device, resulting in enhancement in average VOC from ∼1.2 V in the nonaged case to ∼1.4 V in the aged case. Furthermore, the device using an aged SnCl2 solution also exhibits a much better long-term stability than that made of the fresh solution. These achievements in dopant/additive-free CsPbI2Br solar cells can be useful for future research on CsPbI2Br and tandem solar cells.
Scientific journal, English

Near-Infrared Emission from Tin-Lead (Sn-Pb) Alloyed Perovskite Quantum Dots by Sodium Doping.
Feng Liu; Junke Jiang; Yaohong Zhang; Chao Ding; Taro Toyoda; Shuzi Hayase; Ruixiang Wang; Shuxia Tao; Qing Shen
Angewandte Chemie (International ed. in English), 59, 22, 8421-8424, 25 May 2020, True, Phase-stable CsSnx Pb1-x I3 perovskite quantum dots (QDs) hold great promise for optoelectronic applications owing to their strong response in the near-infrared region. Unfortunately, optimal utilization of their potential is limited by the severe photoluminescence (PL) quenching, leading to extremely low quantum yields (QYs) of approximately 0.3 %. The ultra-low sodium (Na) doping presented herein is found to be effective in improving PL QYs of these alloyed QDs without alerting their favourable electronic structure. X-ray photoelectron spectroscopy (XPS) studies suggest the formation of a stronger chemical interaction between I- and Sn2+ ions upon Na doping, which potentially helps to stabilize Sn2+ and suppresses the formation of I vacancy defects. The optimized PL QY of the Na-doped QDs reaches up to around 28 %, almost two orders of magnitude enhancement compared with the pristine one.
Scientific journal, English

Boosting the Conversion Efficiency Over 20% in MAPbI3 Perovskite Planar Solar Cells by Employing a Solution-Processed Aluminum-Doped Nickel Oxide Hole Collector.
Bhaskar Parida; Saemon Yoon; Jun Ryu; Shuzi Hayase; Sang Mun Jeong; Dong-Won Kang
ACS applied materials & interfaces, 12, 20, 22958-22970, 20 May 2020, True, Recently, nickel oxide (NiOx) thin films have been used as an efficient and robust hole transport layer (HTL) in inverted planar perovskite solar cells (IP-PSCs) to replace costly and unstable organic transport materials. However, the power conversion efficiency (PCE) of most IP-PSCs using NiOx HTLs is rather limited below 20% due to insufficient electronic conductivity of the NiOx. In this work, solution-processed Al-doped NiOx (ANO) films are suggested as HTLs for low-cost and stable IP-PSCs. The electrical conductivity of the NiOx film is significantly enhanced by Al doping, which effectively reduces the nonradiative recombination losses at the HTL-perovskite interfaces and boosts hole extraction/transportation. The device with undoped NiOx shows the best PCE of 16.56%, whereas ANO HTL (5% doping) contributes to achieving a PCE of 20.84%, which outperforms other CH3NH3PbI3 IP-PSCs with NiOx-based HTLs reported to date. Moreover, a reliability test (1728 h storage) shows that the performance stability is enhanced by approximately 11% by employing ANO HTLs. This investigation into ANO HTLs provides a new guideline for the further development of highly efficient and reliable IP-PSCs using low-cost and robust metal oxide HTLs.
Scientific journal, English

Surface-Modified Graphene Oxide/Lead Sulfide Hybrid Film-Forming Ink for High-Efficiency Bulk Nano-Heterojunction Colloidal Quantum Dot Solar Cells.
Yaohong Zhang; Guohua Wu; Chao Ding; Feng Liu; Dong Liu; Taizo Masuda; Kenji Yoshino; Shuzi Hayase; Ruixiang Wang; Qing Shen
Nano-micro letters, 12, 1, 111-111, 16 May 2020, True
Scientific journal, English

Synthesis, photophysical characterization and dye adsorption behavior in unsymmetrical squaraine dyes with varying anchoring groups
Ajendra Kumar Vats; Anusha Pradhan; Shuzi Hayase; Shyam S. Pandey
Journal of Photochemistry and Photobiology A: Chemistry, Elsevier B.V., 394, 01 May 2020
Scientific journal, English

Enhanced Device Performance with Passivation of the TiO2 Surface Using a Carboxylic Acid Fullerene Monolayer for a SnPb Perovskite Solar Cell with a Normal Planar Structure.
Kengo Hamada; Ryo Tanaka; Muhammad Akmal Kamarudin; Qing Shen; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Taro Toyoda; Tingli Ma; Dong-Won Kang; Shuzi Hayase
ACS applied materials & interfaces, 12, 15, 17776-17782, 15 Apr. 2020, True, Research on tin-lead (SnPb) perovskite solar cells (PSCs) has gained popularity in recent years because of their low band gap, which could be applied to tandem solar cells. However, most of the work is based on inverted PSCs using PEDOT:PSS as the hole-transport layer as normal-structure PSCs show lower efficiency. In this work, the reason behind the low efficiency of normal-structure SnPb PSCs is elucidated and surface passivation has been tested as a method to overcome the problem. In the case of normal PSCs, at the interface between the titania layer and SnPb perovskite, there are many carrier traps observed originating from Ti-O-Sn bonds. In order to avoid the direct contact between titania and the SnPb perovskite layer, the titania surface is passivated with carboxylic acid C60 resulting in an efficiency increase from 5.14 to 7.91%. This will provide a direction of enhancing the efficiency of the normal-structure SnPb PSCs through heterojunction engineering.
Scientific journal, English

Reducing trap density and carrier concentration by a Ge additive for an efficient quasi 2D/3D perovskite solar cell
Chi Huey Ng; Kengo Hamada; Gaurav Kapil; Muhammad Akmal Kamarudin; Zhen Wang; Satoshi Likubo; Qing Shen; Kenji Yoshino; Takashi Minemoto; Shuzi Hayase
Journal of Materials Chemistry A, 8, 6, 2962-2968, 14 Feb. 2020, Peer-reviwed
Scientific journal

Trioctylphosphine Oxide Acts as Alkahest for SnX2/PbX2: A General Synthetic Route to Perovskite ASnxPb1-xX3 (A = Cs, FA, MA; X = Cl, Br, I) Quantum Dots
Feng Liu; Yaohong Zhang; Chao Ding; Kentaro Kawabata; Yasuha Yoshihara; Taro Toyoda; Shuzi Hayase; Takashi Minemoto; Ruixiang Wang; Qing Shen
Chemistry of Materials, American Chemical Society, 32, 3, 1089-1100, 11 Feb. 2020
Scientific journal, English

Photoexcited hot and cold electron and hole dynamics at FAPbI3 perovskite quantum dots/metal oxide heterojunctions used for stable perovskite quantum dot solar cells
Chao Ding; Feng Liu; Yaohong Zhang; Daisuke Hirotani; Xing Rin; Shuzi Hayase; Takashi Minemoto; Taizo Masuda; Ruixiang Wang; Qing Shen
Nano Energy, Elsevier Ltd, 67, 01 Jan. 2020
Scientific journal, English

Interface engineering using Y2O3 scaffold to enhance the thermoelectric performance of CsSnI3 thin film,
Ajay Kumar Baranwal; Shrikant Saini; Zhen Wang; Daisuke Hirotani; Tomohide Yabuki; Koji Miyazaki; Shuzi Hayase
Organic Electronics (Elsevier), 2020, 76, 105488. https://doi.org/10.1016/j.orgel.2019.105488, https://doi.org/10.1016/j.orge, 2020, Peer-reviwed
Scientific journal, English

Synthesis of monodispersed silver particles: Synthetic techniques to control shapes, particle size distribution and lightness of silver particles
Kanetaro Sannohe; Tingli Ma; Shuzi Hayase
Advanced Powder Technology, Elsevier B.V., 30, 12, 3088-3098, 01 Dec. 2019
Scientific journal, English

Lead-free tin halide perovskite solar cells beyond 10 % efficiency
Muhammad Akmal Kamarudin; Daisuke Hirotani; Zhen Wang; Kengo Hamada; Kohei Nishimura; Qing Shen; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Shuzi Hayase
Proceedings of the 4th Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics, Fundació Scito, 14 Oct. 2019
International conference proceedings

La-doped SnO2 as ETL for efficient planar-structure hybrid perovskite solar cells
Zhenhua Xu; Siow Hwa Teo; Liguo Gao; Zhanglin Guo; Yusuke Kamata; Shuzi Hayase; Tingli Ma
ORGANIC ELECTRONICS, 73, 62-68, Oct. 2019
Scientific journal, English

Role of device architecture and AlO_X interlayer in organic Schottky diodes and their interpretation by analytical modeling
Nikita Kumari; Manish Pandey; Kengo Hamada; Daisuke Hirotani; Shuichi Nagamatsu; Shuzi Hayase; Shyam S. Pandey
Journal of Applied Physics, AIP Publishing, 126, 12, 125501-125501, 28 Sep. 2019
Scientific journal

Suppression of charge carrier recombination in lead-free tin halide perovskite via lewis base post-treatment
Muhammad Akmal Kamarudin; Daisuke Hirotani; Zhen Wang; Kengo Hamada; Kohei Nishimura; Qing Shen; Taro Toyoda; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Shuzi Hayase
Journal of Physical Chemistry Letters, 10, 17, 5277-5283, 05 Sep. 2019, Peer-reviwed, True
Scientific journal, English

Relationship between Lattice Strain and Efficiency for Sn-Perovskite Solar Cells
Kohei Nishimura; Daisuke Hirotani; Muhammad Akmal Kamarudin; Qing Shen; Taro Toyoda; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Shuzi Hayase
ACS Applied Materials and Interfaces, 11, 34, 31105-31110, 28 Aug. 2019, Peer-reviwed, True
Scientific journal, English

Strain Relaxation and Light Management in Tin-Lead Perovskite Solar Cells to Achieve High Efficiencies
Gaurav Kapil; Takeru Bessho; Chi Huey Ng; Kengo Hamada; Manish Pandey; Muhammad Akmal Kamarudin; Daisuke Hirotani; Takumi Kinoshita; Takashi Minemoto; Qing Shen; Taro Toyoda; Takurou N. Murakami; Hiroshi Segawa; Shuzi Hayase
ACS Energy Letters, 4, 8, 1991-1998, 09 Aug. 2019, Peer-reviwed
Scientific journal

Wide wavelength photon harvesting in dye-sensitized solar cells utilizing cobalt complex redox electrolyte: Implication of surface passivation
Anusha Pradhan; Maryala Sai Kiran; Gaurav Kapil; Shuzi Hayase; Shyam S. Pandey
Solar Energy Materials and Solar Cells, Elsevier B.V., 195, 122-133, 15 Jun. 2019
Scientific journal, English

Niobium Incorporation into CsPbI2Br for Stable and Efficient All-Inorganic Perovskite Solar Cells.
Zhanglin Guo; Shuai Zhao; Anmin Liu; Yusuke Kamata; Siowhwa Teo; Shuzhang Yang; Zhenhua Xu; Shuzi Hayase; Tingli Ma
ACS applied materials & interfaces, 11, 22, 19994-20003, 05 Jun. 2019, True, All-inorganic perovskites are attracting increasing attention due to their superior thermal stability than that of the traditional CH3NH3PbI3, while their inferior phase stability in ambient conditions is still an unsolved issue. Here, for the first time, we report the incorporation of niobium (Nb5+) ions into the CsPbI2Br perovskite. Results indicate that Nb5+ can effectively stabilize the photoactive α-CsPbI2Br phase by the possible substitution of Pb2+. With 0.5% Nb doping, the carbon electrode-based all-inorganic perovskite solar cells achieved a high photoconversion efficiency value of 10.42%, 15% higher than that of the control device. The Nb5+ incorporation reduces the charge recombination in the perovskite, leading to a champion Voc value of 1.27 V and a negligible hysteresis effect. This work explicates the high compatibility of all-inorganic perovskite materials and unlocks the opportunities for the use of high-valence ions for perovskite property modification.
Scientific journal, English

2D positional profiling of orientation and thickness uniformity in the semiconducting polymers thin films
Nikita Kumari; Atul S.M. Tripathi; Shifumi Sadakata; Manish Pandey; Shuichi Nagamatsu; Shuzi Hayase; Shyam S. Pandey
Organic Electronics, Elsevier {BV}, 68, 221-229, May 2019, Peer-reviwed
Scientific journal

Xanthate-induced sulfur doped all-inorganic perovskite with superior phase stability and enhanced performance
Zhen Wang; Ajay K. Baranwal; Muhammad Akmal kamarudin; chi huey Ng; Manish Pandey; Tingli Ma; Shuzi Hayase
Nano Energy, 59, 258-267, May 2019, Peer-reviwed
Scientific journal, English

Passivation of Grain Boundary by Squaraine Zwitterions for Defect Passivation and Efficient Perovskite Solar Cells
Zhen Wang; Anusha Pradhan; Muhammad Akmal kamarudin; Manish Pandey; Shyam S. Pandey; Putao Zhang; Chi huey Ng; Atul S.M. Tripathi; Tingli Ma; Shuzi Hayase
ACS Applied Materials & Interfaces, American Chemical Society ({ACS}), 11, 10, 10012-10020, 13 Mar. 2019, Peer-reviwed, True, Unavoidable defects in grain boundaries (GBs) are detrimental and critically influence the organometal halide perovskite performance and stability. To address this issue, semiconducting molecules have been employed to passivate traps along perovskite GBs. Here, we designed and synthesized three squaraine molecules (SQ) with zwitterionic structure to interact with under-coordinated Pb2+ and passivate Pb-I antisite defects. Density functional theory calculation shows symmetric O atoms could coordinate with perovskite grains simultaneously, resulting in continuous charge distribution at the SQ-perovskite interface. The energetic traps distribution in CH3NH3PbI3 perovskite is influenced significantly by the interaction between SQ and perovskite as analyzed by thermally stimulated current, in which the deep-level defects are considerably reduced due to efficient SQ passivation. In addition, we explore how SQ molecules with different energy offset affect the charge extraction, which is suggested to facilitate exciton separation at the perovskite-SQ interface. These benefits lead to enhanced perovskite efficiency from 15.77 to 18.83% with the fill factor approaching 80%, which is among the highest efficiency reported for MAPbI3 solar cells fabricated in an ambient environment at 60% relative humidity (RH). Considerable retardation of perovskite device degradation was achieved, retaining 90% of initial efficiency when kept 600 h at 60 ± 5% RH.
Scientific journal, English

The interparticle distance limit for multiple exciton dissociation in PbS quantum dot solid films.
Naoki Nakazawa; Yaohong Zhang; Feng Liu; Chao Ding; Kanae Hori; Taro Toyoda; Yingfang Yao; Yong Zhou; Shuzi Hayase; Ruixiang Wang; Zhigang Zou; Qing Shen
Nanoscale horizons, 4, 2, 445-451, 01 Mar. 2019, True, Understanding the behaviour of multiple exciton dissociation in quantum dot (QD) solid films is of fundamental interest and paramount importance for improving the performance of quantum dot solar cells (QDSCs). Unfortunately, the charge transfer behaviour of photogenerated multiple exciton in QD solid films is not clear to date. Herein, we systematically investigate the multiple exciton charge transfer behaviour in PbS QD solid films by using ultrafast transient absorption spectroscopy. We observe that the multiple exciton charge transfer rate within QD ensembles is exponentially enhanced as the interparticle distance between the QDs decreases. Biexciton and triexciton dissociation between adjacent QDs occurs via a charge transfer tunneling effect just like single exciton, and the charge tunneling constants of the single exciton (β1: 0.67 ± 0.02 nm-1), biexciton (β2: 0.68 ± 0.05 nm-1) and triexciton (β3: 0.71 ± 0.01 nm-1) are obtained. More importantly, for the first time, the interparticle distance limit (≤4.3 nm) for multiple exciton charge transfer between adjacent QDs is found for the extraction of multiple excitons rapidly before the occurrence of Auger recombination. This result points out a vital and necessary condition for the use of multiple excitons produced in PbS QD films, especially for their applications in QDSCs.
Scientific journal, English

GeI 2 Additive for High Optoelectronic Quality CsPbI 3 Quantum Dots and Their Application in Photovoltaic Devices
Feng Liu; Chao Ding; Yaohong Zhang; Taichi Kamisaka; Qian Zhao; Joseph M. Luther; Taro Toyoda; Shuzi Hayase; Takashi Minemoto; Kenji Yoshino; Bing Zhang; Songyuan Dai; Junke Jiang; Shuxia Tao; Qing Shen
Chemistry of Materials, American Chemical Society, 31, 3, 798-807, 12 Feb. 2019
Scientific journal, English

The Role of Lanthanum in a Nickel Oxide-Based Inverted Perovskite Solar Cell for Efficiency and Stability Improvement.
Siowhwa Teo; Zhanglin Guo; Zhenhua Xu; Chu Zhang; Yusuke Kamata; Shuzi Hayase; Tingli Ma
ChemSusChem, 12, 2, 518-526, 24 Jan. 2019, True, A high-performing inverted perovskite solar cell (PSC) always relies on the hole transporting layer (HTL) quality and its interfaces. This work investigates the impact of La incorporation within the NiOx matrix for defects passivation, thus leading to high charge extraction ability and stability without compromising its power conversion efficiency. In the presence of La, the La-NiOx quality is clearly improved; without the formation of pinholes. In addition, the inclusion of La alters the energy band alignment; consequently, enhancing the hole transportation and widening the Voc (>1 V), as compared to the pristine NiOx . The beneficial effect of La was further revealed through the photoluminescence measurement and density of states (DOS) analysis, in which trap states are passivated by La. More importantly, the perovskite solar cell, with La-NiOx as the HTL, exhibits 21 % enhancement in efficiency and a remarkable stability that is greater than that of pristine NiOx . This also unlocks an opportunity for commercialization.
Scientific journal, English

Surface coatings for improving solar cell efficiencies
Qing Shen; Chao Ding; Yaohong Zhang; Feng Liu; Taro Toyoda; Kenji Yoshino; Takashi Minemoto; Shuzi Hayase
Optics InfoBase Conference Papers, OSA - The Optical Society, 2019, 2019
International conference proceedings, English

Growth of halide perovskites thin films for thermoelectric applications
Shrikant Saini; Ajay Kumar Baranwal; Tomohide Yabuki; Shuzi Hayase; Koji Miyazaki
MRS Advances, Materials Research Society, 4, 30, 1719-1725, 2019
Scientific journal, English

Achievable high: V oc of carbon based all-inorganic CsPbIBr 2 perovskite solar cells through interface engineering
Zhanglin Guo; Siowhwa Teo; Zhenhua Xu; Chu Zhang; Yusuke Kamata; Shuzi Hayase; Tingli Ma
Journal of Materials Chemistry A, Royal Society of Chemistry, 7, 3, 1227-1232, 2019
Scientific journal, English

Improving Photovoltaic Performance of ZnO Nanowires Based Colloidal Quantum Dot Solar Cells via SnO2 Passivation Strategy
Shuhei Ozu; Yaohong Zhang; Hironobu Yasuda; Yukiko Kitabatake; Taro Toyoda; Masayuki Hirata; Kenji Yoshino; Kenji Katayama; Shuzi Hayase; Ruixiang Wang; Qing Shen
Front. Energy Res, 7, 11-19, 2019, Peer-reviwed, Invited
Scientific journal, English

Hot-injection and ultrasonic irradiation syntheses of Cs2SnI6 quantum dot using Sn long-chain amino-complex
Tsuguo Koyanagi; Gaurav Kapil; Yuhei Ogomi; Kenji Yoshino; Qin Shen; Taro Toyoda; Takurou N. Murakami; Hiroshi Segawa; Shuzi Hayase
J Nanopart Res, 2020, 22:69 https://doi.org/10.1007/s11051-020-04787-w., https://doi.org/10.1007/s11051, 3, 2019, Peer-reviwed
Scientific journal, English

Hybrid-Halide Perovskite Thin Film Growth for Thermoelectric Applications,
SHRIKANT SAINI; AJAY KUMAR BARANWAL; TOMOHIDE YABUKI; SHUZI HAYASE; KOJI MIYAZAKI
Journal of ELECTRONIC MATERIALS https://doi.org/10.1007/s11664-020-07958-6., https://doi.org/10.1007/s11664, https://doi.org/10.1007/s11664, 2019, Peer-reviwed
Scientific journal, English

Theoretical analysis of band alignment at back junction in Sn-Ge perovskite solar cells with inverted p-i-n structure
Takashi Minemoto; Yu Kawano; Takahito Nishimura; Qing Shen; Kenji Yoshino; Satoshi Iikubo; Shuzi Hayase
SOLMAT, 10.1016/j.solmat.2019.110208., 10.1016/j.solmat.2019.110208., 2019, Peer-reviwed
Scientific journal, English

Delocalized Molecule Surface Electronic Modification for Enhanced Performance and High Environmental Stability of CsPbI2Br Perovskite Solar Cells
Zhen Wang; Ajay K. Baranwal; Muhammad Akmal kamarudin; Putao Zhang; Gaurav Kapil; Tingli Ma; Shuzi Hayase
Nano Energy, https://doi.org/10.1016/j.nanoen.2019.104180, https://doi.org/10.1016/j.nano, 2019, Peer-reviwed
Scientific journal, English

12. Growth of Amorphous Passivation Layer Using Phenethylammonium Iodide for High-Performance Inverted Perovskite Solar Cells
Fan Zhang; Qinxun Huang; Jun Song; Yaohong Zhang; Chao Ding; Feng Liu; Dong Liu; Xiaobin Li; Hironobu Yasuda; Koji Yoshida; Junle Qu; Shuzi Hayase
Sol. RRL 2019, 1900243, 1900243, Sol. RRL 2019, 1900243, 190024, 2, 2019, Peer-reviwed
Scientific journal, English

Dependence of ITO-coated flexible substrates in the performance and bending durability of perovskite solar cells
Manish Pandey; Zhen Wang; Gaurav Kapil; Ajay K. Baranwal; Daisuke Hirotani; Kengo Hamada; Shuzi Hayase
Advanced Engineering Materials, 2019, 1900288, DOI:10.1002/adem.20190028., 8, 2019, Peer-reviwed
Scientific journal, English

Efficient, Hysteresis Free, Inverted Planar Flexible Perovskite Solar Cells via Perovskite Engineering and Stability in Cylindrical Encapsulation,
Manish Pandey; Gaurav Kapil; Kazuhiko Sakamoto; Daisuke Hirotani; Muhammad Akmal Kamrudin; Zhen Wang; Kengo Hamada; Daishiro Nomura; Hyo-Gyoung Kang; Hideaki Nagayoshi; Masaki Nakamura; Masahiro Hayashi; Takatoshi Nomura; Shuzi Hayase
Sustainable Energy & Fuels, 2019,3, 1739-1748,, Royal Society of Chemistry (RSC), DOI:10.1039/c9se00153k, 7, 1739-1748, 2019, Peer-reviwed,

Efficient flexible perovskite solar cells were obtained by compositional engineering. Cylindrically encapsulated devices retained 90% of the device efficiency after 6000 h.

Scientific journal, English

Solution-processed intermediate-band solar cells with lead sulfide quantum dots and lead halide perovskites
Hiroji Hosokawa; Ryo Tamaki; Takuya Sawada; Akinori Okonogi; Haruyuki Sato; Yuhei Ogomi; Shuzi Hayase; Yoshitaka Okada; Toshihiro Yano
Nature Communications, Vol. 10,43, (2019), Nature Communications, Vol. 1, 1, 43-43, 2019, Peer-reviwed, True, The intermediate-band solar cell (IBSC) with quantum dots and a bulk semiconductor matrix has potential for high power conversion efficiency, exceeding the Shockley-Queisser limit. However, the IBSCs reported to date have been fabricated only by dry process and their efficiencies are limited, because their photo-absorption layers have low particle density of quantum dots, defects due to lattice strain, and low bandgap energy of bulk semiconductors. Here we present solution-processed IBSCs containing photo-absorption layers where lead sulfide quantum dots are densely dispersed in methylammonium lead bromide perovskite matrices with a high bandgap energy of 2.3 eV under undistorted conditions. We confirm that the present IBSCs exhibit two-step photon absorption via intermediate-band at room temperature by inter-subband photocurrent spectroscopy.
Scientific journal, English

Effect of Precursor Solution Aging on the Thermoelectric Performance of CsSnI3 Thin Film
Ajay Kumar Baranwal; Shrikant Saini; Zhen Wang; Kengo Hamada; Daisuke Hirotani; Kohei Nishimura; Muhammad Akmal Kamarudin; Gaurav Kapil; Tomohide Yabuki; Satoshi Iikubo; Qing Shen; Koji Miyazaki; Shuzi Hayase
Journal of Electronic Materials, 49, 5, 2698-2703, 2019, Peer-reviwed
Scientific journal

Pb-free Sn perovskite solar cells doped with samarium iodide
Kengo Hamada; Daisuke Hirotani; Muhammad Akmal Kamarudin; Kohei Nishimura; Qing Shen; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Taro Toyoda; Shuzi Hayase
Chemistry Letters, 48, 8, 836-839, 2019, Peer-reviwed
Scientific journal

The effect of transparent conductive oxide substrate on the efficiency of snge-perovskite solar cells
Kengo Hamada; Muhammad Akmal Kamarudin; Wang Zhen; Daisuke Hirotani; Qing Shen; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Taro Toyoda; Shuzi Hayase
Journal of Photopolymer Science and Technology, 32, 4, 597-602, 2019, Peer-reviwed
Scientific journal

Structured crystallization for efficient all-inorganic perovskite solar cells with high phase stability
Zhen Wang; Ajay K. Baranwal; Muhammad Akmal Kamarudin; Yusuke Kamata; Chi Huey Ng; Manish Pandey; Tingli Ma; Shuzi Hayase
Journal of Materials Chemistry A, 7, 35, 20390-20397, 2019, Peer-reviwed
Scientific journal

Vacuum deposition of CsPbI3 layers on textured Si for Perovskite/Si tandem solar cells
Keitaro Hamada; Kyosuke Yonezawa; Kohei Yamamoto; Tetsuya Taima; Shuzi Hayase; Noboru Ooyagi; Yuzo Yamamoto; Keisuke Ohdaira
Japanese Journal of Applied Physics 58, SBBF06, 2019., Japanese Journal of Applied Ph, SBBF06, 2019, Peer-reviwed
Scientific journal, English

Role of GeI2 and SnF2 Additives for SnGe Perovskite Solar Cells
Ng, C.H; Nishimura K; Ito N; Hamada, K; Hirotani, D; Yang, F; Wang Z; likubo, S; Shen, Q; Yoshino K; Minemoto, T; Hayase, S
Nano Energy, Volume 58, April 2019, Pages 130-137,, Elsevier BV, https://doi.org/10.1016/j.nano, 130-137, 2019, Peer-reviwed
Scientific journal, English

Preparation of Perovskite Films under Liquid Nitrogen Atmosphere for High Efficiency Perovskite Solar Cells,
Zhang, P; Yang, F; Kapil, G; Ng, C. H; Ma, T; Hayase, S
ACS Sustainable Chem. Eng., 7, 3956-3961, 2019, ACS Sustainable Chem. Eng., 7,, 4, 3959-3961, 2019, Peer-reviwed
Scientific journal, English

Melamine Hydroiodide Functionalized MAPbI3 Perovskite with Enhanced Photovoltaic Performance and Stability in Ambient Atmosphere
Yang, F; Kamarudin, A. M; Hirotani, D; Zhang, P; Kapil, G; Ng, C. H; Ma, T; Hayase, S
Solar RRL, 3, 1800275, Jan. 2019, Peer-reviwed
Scientific journal, English

New Tin(II) Fluoride Derivative as a Precursor for Enhancing the Efficiency of Inverted Planar Tin/Lead Perovskite Solar Cells
Teresa S. Ripolles; Daiki Yamasuso; Yaohong Zhang; Muhammad Akmal Kamarudin; Chao Ding; Daisuke Hirotani; Qing Shen; Shuzi Hayase
The Journal of Physical Chemistry C, American Chemical Society ({ACS}), 122, 48, 27284-27291, 06 Dec. 2018, Peer-reviwed
Scientific journal, English

Anisotropic Crystal Growth, Optical Absorption, and Ground-State Energy Level of CdSe Quantum Dots Adsorbed on the (001) and (102) Surfaces of Anatase-TiO2: Quantum Dot-Sensitization System
Taro Toyoda; Qing Shen; Motoki Hironaka; Keita Kamiyama; Hisayoshi Kobayashi; Yasushi Hirose; Shuzi Hayase
The Journal of Physical Chemistry C, American Chemical Society ({ACS}), Dec. 2018, Peer-reviwed

Interfacial Sulfur Functionalization Anchoring SnO2 and CH3NH3PbI3 for Enhanced Stability and Trap Passivation in Perovskite Solar Cells
Zhen Wang; Muhammad Akmal Kamarudin; Ng Chi Huey; Fu Yang; Manish Pandey; Gaurav Kapil; Tingli Ma; Shuzi Hayase
ChemSusChem, 11, 22, 3941-3948, 23 Nov. 2018, Peer-reviwed, True
Scientific journal, English

High Electrical Conductivity 2D MXene Serves as Additive of Perovskite for Efficient Solar Cells.
Zhanglin Guo; Liguo Gao; Zhenhua Xu; Siowhwa Teo; Chu Zhang; Yusuke Kamata; Shuzi Hayase; Tingli Ma
Small (Weinheim an der Bergstrasse, Germany), 14, 47, e1802738, Nov. 2018, True, MXenes, a newly intriguing family of 2D materials, have recently attracted considerable attention owing to their excellent properties such as high electrical conductivity and mobility, tunable structure, and termination groups. Here, the Ti3 C2 Tx MXene is incorporated into the perovskite absorber layer for the first time, which aims for efficiency enhancement. Results show that the termination groups of Ti3 C2 Tx can retard the crystallization rate, thereby increasing the crystal size of CH3 NH3 PbI3 . It is found that the high electrical conductivity and mobility of MXene can accelerate the charge transfer. After optimizing the key parameters, 12% enhancement in device performance is achieved by 0.03 wt% amount of MXene additive. This work unlocks opportunities for the use of MXene as potential materials in perovskite solar cell applications.
Scientific journal, English

Addition Effect of Pyreneammonium Iodide to Methylammonium Lead Halide Perovskite-2D/3D Heterostructured Perovskite with Enhanced Stability
Yang, F; Hirotani, D; Kapil, G; Kamarudin, A. M; Ng, H. C; Zhang Y; Shen, Q; Hayase, S
Advanced Functional Materials, 57, 39, 122745-12749, Nov. 2018, Peer-reviwed
Scientific journal, English

Synthesis and Optoelectrical Characterization of Novel Squaraine Dyes Derived from Benzothiophene and Benzofuran.
G Hanumantha Rao; Manish Pandey; Kamatham Narayanaswamy; Ravulakollu Srinivasa Rao; Shyam S Pandey; Shuzi Hayase; Surya Prakash Singh
ACS omega, 3, 10, 13919-13927, 31 Oct. 2018, True, Synthesis and photophysical characterizations of two novel small molecules SQ-BEN-THI and SQ-BEN-FUR with D-A-D molecular structure consisting of squaraine as central unit and benzothiophene and benzofuran as end groups are being reported. Apart from very sharp and intense light absorption by these molecular sensitizers in near-infrared (NIR) wavelength region, their possibility as small molecular organic semiconductor was also explored after fabricating organic field-effect transistors (OFETs). Results obtained from photophysical, electrochemical, and quantum chemical studies were combined to elucidate the structural and optoelectronic properties. Electrical characterization pertaining to the charge-transport properties carried after OFET fabrication exhibited field-effect mobilities of 4.0 × 10-5 and 5.4 × 10-5 cm2/(V s) for SQ-BEN-THI and SQ-BEN-FUR, respectively. After thermal annealing at 130 °C, the field-effect mobility was found to increase for both squaraine dyes. Relatively facile carrier transport in SQ-BEN-FUR compared to that of SQ-BEN-THI could be attributed to relatively higher backbone planarity as indicated from optimized molecular structure obtained after density functional theory calculations. This work may guide for further molecular design and synthesis of novel squaraine dyes for high-performance OFET applications.
Scientific journal, English

Perovskite solar cells consisting of mixed metal SnGe perovskite as light absorber and role of the Ge in the solar cell
Shuzi Hayase; Chi-Huey Nga; Kengo Hamada; Daisuke Hirotani; Akmal Kamarudin; Qing Shen; Satoshi Iikubo; Kenji Yoshino; Takashi Minemoto
Proceedings of the 3rd International Conference on Perovskite and Organic Photovoltaics and Optoelectronics, Fundació Scito, 23 Oct. 2018
International conference proceedings

Synthesis and Photophysical Characterization of Unsymmetrical Squaraine Dyes for Dye-Sensitized Solar Cells Utilizing Cobalt Electrolytes
Anusha Pradhan; Maryala Sai Kiran; Gaurav Kapil; Shuzi Hayase; Shyam S. Pandey
ACS Applied Energy Materials, American Chemical Society, 1, 9, 4545-4553, 24 Sep. 2018
Scientific journal, English

All-Inorganic CsPb1−xGexI2Br Perovskite with Enhanced Phase Stability and Photovoltaic Performance
Fu Yang; Daisuke Hirotani; Gaurav Kapil; Muhammad Akmal Kamarudin; Chi Huey Ng; Yaohong Zhang; Qing Shen; Shuzi Hayase
Angewandte Chemie - International Edition, German Chemical Society, 57, 39, 12745-12749, 24 Sep. 2018, Peer-reviwed, True
Scientific journal, English

Performance Enhancement of Mesoporous TiO2-Based Perovskite Solar Cells by SbI3 Interfacial Modification Layer
Putao Zhang; Fu Yang; Muhammad Akmal Kamarudin; Chi Huey Ng; Gaurav Kapil; Tingli Ma; Shuzi Hayase
ACS Applied Materials & Interfaces, 10, 35, 29630-29637, 05 Sep. 2018, Peer-reviwed, True
Scientific journal, English

Recombination Suppression in PbS Quantum Dot Heterojunction Solar Cells by Energy-Level Alignment in the Quantum Dot Active Layers.
Chao Ding; Yaohong Zhang; Feng Liu; Naoki Nakazawa; Qingxun Huang; Shuzi Hayase; Yuhei Ogomi; Taro Toyoda; Ruixiang Wang; Qing Shen
ACS applied materials & interfaces, 10, 31, 26142-26152, 08 Aug. 2018, True, Using spatial energy-level gradient engineering with quantum dots (QDs) of different sizes to increase the generated carrier collection at the junction of a QD heterojunction solar cell (QDHSC) is a hopeful route for improving the energy-conversion efficiency. However, the results of current related research have shown that a variable band-gap structure in a QDHSC will create an appreciable increase, not in the illumination current density, but rather in the fill factor. In addition, there are a lack of studies on the mechanism of the effect of these graded structures on the photovoltaic performance of QDHSCs. This study presents the development of air atmosphere solution-processed TiO2/PbS QDs/Au QDHSCs by engineering the energy-level alignment (ELA) of the active layer via the use of a sorted order of differently sized QD layers (four QD sizes). In comparison to the ungraded device (without the ELA), the optimized graded architecture (containing the ELA) solar cells exhibited a great increase (21.4%) in short-circuit current density ( Jsc). As a result, a Jsc value greater than 30 mA/cm2 has been realized in planar, thinner absorption layer (∼300 nm) PbS QDHSCs, and the open-circuit voltage ( Voc) and power-conversion efficiency (PCE) were also improved. Through characterization by the light intensity dependences of the Jsc and Voc and transient photovoltage decay, we find that (i) the ELA structure, serving as an electron-blocking layer, reduces the interfacial recombination at the PbS/anode interface, and (ii) the ELA structure can drive more carriers toward the desirable collection electrode, and the additional carriers can fill the trap states, reducing the trap-assisted recombination in the PbS QDHSCs. This work has clearly elucidated the mechanism of the recombination suppression in the graded QDHSCs and demonstrated the effects of ELA structure on the improvement of Jsc. The charge recombination mechanisms characterized in this work would be able to shed light on further improvements of QDHSCs, which could even benefit other types of solar cells.
Scientific journal, English

Magnesium-Doped MAPbI3 Perovskite Layers for Enhanced Photovoltaic Performance in Humid Air Atmosphere
Fu Yang; Muhammad Akmal Kamarudin; Gaurav Kapil; Daisuke Hirotani; Putao Zhang; Chi Huey Ng; Tingli Ma; Shuzi Hayase
ACS Applied Materials & Interfaces, American Chemical Society ({ACS}), 10, 29, 24543-24548, 25 Jul. 2018, Peer-reviwed, True, Despite the high efficiency of MAPbI3 perovskite solar cells, the long term stability and degradation in humid atmosphere are issues that still needed to be addressed. In this work, magnesium iodide (MgI2) was first successfully used as a dopant into MAPbI3 perovskite prepared in humid air atmosphere. Mg doping decreased the valence band level, which was determined from photoelectron yield spectroscopy. Compared to the pristine MAPbI3 perovskite film, the 1.0% Mg-doped perovskite film showed increased crystal grain size and formation of pinhole-free perovskite film. Performance of the solar cell was increased from 14.2% of the doping-free solar cell to 17.8% of 1.0% Mg-doped device. Moreover, 90% of the original power conversion efficiency was still retained after storage in 30-40% relative humidity for 600 h.
Scientific journal, English

Enhanced Crystallization by Methanol Additive in Antisolvent for Achieving High-Quality MAPbI3 Perovskite Films in Humid Atmosphere
Fu Yang; Muhammad Akmal Kamarudin; Putao Zhang; Gaurav Kapil; Tingli Ma; Shuzi Hayase
ChemSusChem, Wiley, 11, 14, 2348-2357, 20 Jul. 2018, Peer-reviwed, True
Scientific journal, English

Minute quantities of hexagonal nanoplates PtFe alloy with facile operating conditions enhanced electrocatalytic activity and durability for oxygen reduction reaction
Nannan Wang; Yanqiang Li; Zhanglin Guo; Huan Li; Shuzi Hayase; Tingli Ma
Journal of Alloys and Compounds, Elsevier Ltd, 752, 23-31, 05 Jul. 2018, Peer-reviwed
Scientific journal, English

Highly Efficient 17.6% Tin-Lead Mixed Perovskite Solar Cells Realized through Spike Structure
Gaurav Kapil; Teresa S. Ripolles; Kengo Hamada; Yuhei Ogomi; Takeru Bessho; Takumi Kinoshita; Jakapan Chantana; Kenji Yoshino; Qing Shen; Taro Toyoda; Takashi Minemoto; Takurou N. Murakami; Hiroshi Segawa; Shuzi Hayase
Nano Letters, ACS, 18, 6, 3600-3607, 13 Jun. 2018, Peer-reviwed, True
Scientific journal, English

Anomalous Dielectric Behavior of a Pb/Sn Perovskite: Effect of Trapped Charges on Complex Photoconductivity
Kento Yamada; Ryosuke Nishikubo; Hikaru Oga; Yuhei Ogomi; Shuzi Hayase; Shohei Kanno; Yutaka Imamura; Masahiko Hada; Akinori Saeki
ACS Photonics, American Chemical Society ({ACS}), 5, 8, 3189-3197, Jun. 2018, Peer-reviwed
Scientific journal, English

Dependence of Acetate-Based Antisolvents for High Humidity Fabrication of CH3NH3PbI3 Perovskite Devices in Ambient Atmosphere
Fu Yang; Gaurav Kapil; Putao Zhang; Zhaosheng Hu; Muhammad Akmal Kamarudin; Tingli Ma; Shuzi Hayase
ACS Applied Materials & Interfaces, American Chemical Society ({ACS}), 10, 19, 16482-16489, 16 May 2018, Peer-reviwed, True, High-efficiency perovskite solar cells (PSCs) need to be fabricated in the nitrogen-filled glovebox by the atmosphere-controlled crystallization process. However, the use of the glovebox process is of great concern for mass level production of PSCs. In this work, notable efficient CH3NH3PbI3 solar cells can be obtained in high humidity ambient atmosphere (60-70% relative humidity) by using acetate as the antisolvent, in which dependence of methyl, ethyl, propyl, and butyl acetate on the crystal growth mechanism is discussed. It is explored that acetate screens the sensitive perovskite intermediate phases from water molecules during perovskite film formation and annealing. It is revealed that relatively high vapor pressure and high water solubility of methyl acetate (MA) leads to the formation of highly dense and pinhole free perovskite films guiding to the best power conversion efficiency (PCE) of 16.3% with a reduced hysteresis. The devices prepared using MA showed remarkable shelf life stability of more than 80% for 360 h in ambient air condition, when compared to the devices fabricated using other antisolvents with low vapor pressure and low water solubility. Moreover, the PCE was still kept at 15.6% even though 2 vol % deionized water was added in the MA for preparing the perovskite layer.
Scientific journal, English

Mixed Sn-Ge Perovskite for Enhanced Perovskite Solar Cell Performance in Air
Nozomi Ito; Muhammad Akmal Kamarudin; Daisuke Hirotani; Yaohong Zhang; Qing Shen; Yuhei Ogomi; Satoshi Iikubo; Takashi Minemoto; Kenji Yoshino; Shuzi Hayase
Journal of Physical Chemistry Letters, 9, 7, 1682-1688, Apr. 2018, Peer-reviwed, True
Scientific journal, English

Rapid Formation and Macroscopic Self-Assembly of Liquid-Crystalline, High-Mobility, Semiconducting Thienothiophene
Manish Pandey; Ashwathanarayana Gowda; Shuichi Nagamatsu; Sandeep Kumar; Wataru Takashima; Shuzi Hayase; Shyam S. Pandey
Advanced Materials Interfaces, Wiley-VCH Verlag, 5, 6, 1700875, 23 Mar. 2018, Peer-reviwed
Scientific journal, English

Anisotropic charge transport in highly oriented films of semiconducting polymer prepared by ribbon-shaped floating film
Atul S. M. Tripathi; Manish Pandey; Shifumi Sadakata; Shuichi Nagamatsu; Wataru Takashima; Shuzi Hayase; Shyam S. Pandey
Applied Physics Letters, American Institute of Physics Inc., 112, 12, 123301, 19 Mar. 2018, Peer-reviwed
Scientific journal, English

Piper Ornatum and Piper Betle as Organic Dyes for TiO2 and SnO2 Dye Sensitized Solar Cells
Azwar Hayat; A. Erwin E. Putra; Novriany Amaliyah; Shuzi Hayase; Shyam. S. Pandey
Journal of Physics: Conference Series, Institute of Physics Publishing, 979, 1, 13 Mar. 2018, Peer-reviwed
International conference proceedings, English

Growth Mechanism of ZnO Thin Films Grown by Spray Pyrolysis Using Diethylzinc Solution
Masato Imai; Marin Watanabe; Himeka Tominaga; Kenji Yoshino; Yuhei Ogomi; Qing Shen; Taro Toyoda; Takashi Minemoto; Shuzi Hayase
Physica Status Solidi (A) Applications and Materials Science, Wiley-VCH Verlag, 215, 4, 1700406, 21 Feb. 2018, Peer-reviwed
Scientific journal, English

Effects of Temperature on Electrochemical Properties of Bismuth Oxide/Manganese Oxide Pseudocapacitor
Chi Huey Ng; Hong Ngee Lim; Shuzi Hayase; Zulkarnain Zainal; Suhaidi Shafie; Nay Ming Huang
Industrial and Engineering Chemistry Research, American Chemical Society, 57, 6, 2146-2154, 14 Feb. 2018, Peer-reviwed
Scientific journal, English

D–π–A Dyes that Contain New Hydantoin Anchoring Groups for Dye-Sensitized Solar Cells
Hisashi Masui; Masato M. Maitani; Shinichiro Fuse; Ayaka Yamamura; Yuhei Ogomi; Shuzi Hayase; Tatsuo Kaiho; Hiroshi Tanaka; Yuji Wada; Takashi Takahashi
Asian Journal of Organic Chemistry, Wiley-VCH Verlag, 7, 2, 458-464, 01 Feb. 2018, Peer-reviwed
Scientific journal, English

Ultrafast Electron Injection from Photoexcited Perovskite CsPbI3 QDs into TiO2 Nanoparticles with Injection Efficiency near 99%
Feng Liu; Yaohong Zhang; Chao Ding; Taro Toyoda; Yuhei Ogomi; Teresa S. Ripolles; Shuzi Hayase; Takashi Minemoto; Kenji Yoshino; Songyuan Dai; Qing Shen
Journal of Physical Chemistry Letters, American Chemical Society, 9, 2, 294-297, 18 Jan. 2018, Peer-reviwed, True
Scientific journal, English

Synthesis of fe, co incorporated in p-doped porous carbon using a metal-organic framework (MOF) precursor as stable catalysts for oxygen reduction reaction
Nannan Wang; Yanqiang Li; Zhanglin Guo; Huan Li; Shuzi Hayase; Tingli Ma
Journal of the Electrochemical Society, Electrochemical Society Inc., 165, 12, G3080-G3086, 2018
Scientific journal, English

Study To Observe the Effect of PbI2 Passivation on Carbon Electrode for Perovskite Solar Cells by Quartz Crystal Microbalance System
Putao Zhang; Gaurav Kapil; Kengo Hamada; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
ACS Sustainable Chemistry & Engineering, 6, 10221-10228, 2018., ACS Sustainable Chemistry & En, 8, 10221-10228, 2018, Peer-reviwed
Scientific journal, English

Enhancement of Charge Ttransport in Quantum Dots Solar Cells by N-butylamine-Assisted Sulfur-crosslinking of PbS Quantum Dots
Zhen, W; Zhaosheng H; Muhammad A. K; Gaurav K; Atul T; Shen Q; Yoshino, K; Minemoto, T; Sham S. P; Hayase, S
Solar Energy, 174, 399-408, 2018, Peer-reviwed
Scientific journal, English

Solution‐Processed Air‐Stable Copper Bismuth Iodide CuBiI3 for Photovoltaics
Zhaoshung, H; Wang, Z; Kapil, G; Tingli Ma, T; Iikubo, S; Minemoto, T; Yopshino, K; Toyoda, T; Shen, Q; Hayase, S
ChemSusChem, Wiley, 11, 17, 2930-2935, 2018, Peer-reviwed, True, Bismuth-based solar cells have been under intensive interest as an efficient non-toxic absorber in photovoltaics. Within this new family of semiconductors, we herein report a new, long-term stable copper bismuth iodide (CuBiI4 ). A solutionprocessed method under air atmosphere is used to prepare the material. The adopted HI-assisted dimethylacetamide (DMA) co-solvent can completely dissolve CuI and BiI3 powders with high concentration compared with other organic solvents. Moreover, the high vapor pressure of tributyl phosphate, selected for the solvent vapor annealing (SVA), enables complete low-temperature (≤70 °C) film preparation, resulting in a stable, uniform, dense CuBiI4 film. The average grain size increases with the precursor concentration, greatly improving the photoluminescence lifetime and hall mobility; a carrier lifetime of 3.03 ns as well as an appreciable hall mobility of 110 cm2  V-1 s-1 were obtained. XRD illustrates that the crystal structure is cubic (space group Fd3m) and favored in the [1 1 1] direction. Moreover, the photovoltaic performance of CuBiI4 was also investigated. A wide bandgap (2.67 eV) solar cell with 0.82 % power conversion efficiency is presented, which exhibits excellent long-term stability over 1008 h under ambient conditions. This air-stable material may give an application in future tandem solar cells as a stable short-wavelength light absorber.
Scientific journal, English

Effect of the Conduction Band Offset on Interfacial Recombination Behavior of the Planar Perovskite Solar Cells
Dinga, C; Zhang, Y; Liu, F; Kitabatake,Y; Hayase, S; Toyoda, T; Yoshino, K; Minemoto, T; Katayama, K; Shen, Q
Nano Energy, Elsevier, 53, 17-26, 2018, Peer-reviwed
Scientific journal, English

Tunable Open Circuit Voltage by Engineering Inorganic Cesium Lead Bromide/Iodide Perovskite Solar Cells,
Ng, C.H; Ripolles, T.S; Hamada, K; Teo, S.H; Lim, H.N; Bisquert, J; Hayase, S
Scientific reports, Nature, 8, 1, 2482-2482, 2018, Peer-reviwed, True, Perovskite solar cells based on series of inorganic cesium lead bromide and iodide mixture, CsPbBr3-xI x , where x varies between 0, 0.1, 0.2, and 0.3 molar ratio were synthesized by two step-sequential deposition at ambient condition to design the variations of wide band gap light absorbers. A device with high overall photoconversion efficiency of 3.98 % was obtained when small amount of iodide (CsPbBr2.9I0.1) was used as the perovskite and spiro-OMeTAD as the hole transport material (HTM). We investigated the origin of variation in open circuit voltage, Voc which was shown to be mainly dependent on two factors, which are the band gap of the perovskite and the work function of the HTM. An increment in Voc was observed for the device with larger perovskite band gap, while keeping the electron and hole extraction contacts the same. Besides, the usage of bilayer P3HT/MoO3 with deeper HOMO level as HTM instead of spiro-OMeTAD, thus increased the Voc from 1.16 V to 1.3 V for CsPbBr3 solar cell, although the photocurrent is lowered due to charge extraction issues. The stability studies confirmed that the addition of small amount of iodide into the CsPbBr3 is necessarily to stabilize the cell performance over time.
Scientific journal, English

Lead Selenide Colloidal Quantum Dot Solar Cells Achieving High Open-Circuit Voltage with One-Step Deposition Strategy
Zhang, Y; Wu, G; Ding, C; Liu, F; Yao, Y; Zhou, Y; Wu, C; Nakazawa, N; Huang, Q; Toyoda, T; Wang, R; Hayase, S; Zou, Z; Shen, Q
Journal of Physical Chemistry Letters, 9, 13, 3598-3603, 2018, Peer-reviwed, True
Scientific journal, English

Understanding charge transfer and recombination by interface engineering for improving the efficiency of PbS quantum dot solar cells
Ding, C; Zhang, Y; Liu, F; Kitabatake, Y; Hayase, S; Toyoda, T; Wang, R; Yoshino, K; Minemoto, T; Shen, Q
Nanoscale Horizons, 3, p.417-429, 2018., RSC, 3, 4, 417-429, 2018, Peer-reviwed, True, In quantum dot heterojunction solar cells (QDHSCs), the QD active layer absorbs sunlight and then transfers the photogenerated electrons to an electron-transport layer (ETL). It is generally believed that the conduction band minimum (CBM) of the ETL should be lower than that of the QDs to enable efficient charge transfer from the QDs to the collection electrode (here, FTO) through the ETL. However, by employing Mg-doped ZnO (Zn1-xMgxO) as a model ETL in PbS QDHSCs, we found that an ETL with a lower CBM is not necessary to realize efficient charge transfer in QDHSCs. The existence of shallow defect states in the Zn1-xMgxO ETL can serve as additional charge-transfer pathways. In addition, the conduction band offset (CBO) between the ETL and the QD absorber has been, for the first time, revealed to significantly affect interfacial recombination in QDHSCs. We demonstrate that a spike in the band structure at the ETL/QD interface is useful for suppressing interfacial recombination and improving the open-circuit voltage. By varying the Mg doping level in ZnO, we were able to tune the CBM, defect distribution and carrier concentration in the ETL, which play key roles in charge transfer and recombination and therefore the device performance. PbS QDHSCs based on the optimized Zn1-xMgxO ETL exhibited a high power conversion efficiency of 10.6%. Our findings provide important guidance for enhancing the photovoltaic performance of QD-based solar cells.
Scientific journal, English

Interface passivation effects on the photovoltaic performance of quantum dot sensitized inverse opal TiO2 solar cells
Hori, K; Zhang, Y; Tusamalee, P; Nakazawa, N; Yoshihara, Y; Wang, R; Toyoda, T; Hayase, S; Shen, Q
Nanomaterials, 8, p.460, 2018, MDPI, 8, 7, 460, 2018, Peer-reviwed, True, Quantum dot (QD)-sensitized solar cells (QDSSCs) are expected to achieve higher energy conversion efficiency than traditional single-junction silicon solar cells due to the unique properties of QDs. An inverse opal (IO)-TiO₂ (IO-TiO₂) electrode is useful for QDSSCs because of its three-dimensional (3D) periodic nanostructures and better electrolyte penetration compared to the normal nanoparticles (NPs)-TiO₂ (NPs-TiO₂) electrode. We find that the open-circuit voltages Voc of the QDSSCs with IO-TiO₂ electrodes are higher than those of QDSSCs with NPs-TiO₂ electrodes. One important strategy for enhancing photovoltaic conversion efficiency of QDSSCs with IO-TiO₂ electrodes is surface passivation of photoanodes using wide-bandgap semiconducting materials. In this study, we have proposed surface passivation on IO-TiO₂ with ZnS coating before QD deposition. The efficiency of QDSSCs with IO-TiO₂ electrodes is largely improved (from 0.74% to 1.33%) because of the enhancements of Voc (from 0.65 V to 0.74 V) and fill factor (FF) (from 0.37 to 0.63). This result indicates that ZnS passivation can reduce the interfacial recombination at the IO-TiO₂/QDs and IO-TiO₂/electrolyte interfaces, for which two possible explanations can be considered. One is the decrease of recombination at IO-TiO₂/electrolyte interfaces, and the other one is the reduction of the back-electron injection from the TiO₂ electrode to QDs. All of the above results are effective for improving the photovoltaic properties of QDSSCs.
Scientific journal, English

Photovoltaic performances of mono- and mixed-halide structures for perovskite solar cell
Ng, C.H; Lim, H.N; Hayase, S; Zainal, Z; Huang, N.M
Renewable and Sustainable Energy Reviews, 90, p.248-274, 2018, Elsevier, 90, 248-274, 2018, Peer-reviwed
Scientific journal, English

Ultrafast selective extraction of hot holes from cesium lead iodide perovskite films
Shen, Q; Ripolles, T.S; Even, J; Zhang, Y; Ding, C; Liu, F; Izuishi, T; Nakazawa, N; Toyoda, T; Ogomi, Y; Hayase, S
Journal of Energy Chemistry, Elsevier, 27, 1170-1174, 2018, Peer-reviwed
Scientific journal, English

Crystal Growth, Exponential Optical Absorption Edge, and Ground State Energy Level of PbS Quantum Dots Adsorbed on the (001), (110), and (111) Surfaces of Rutile-TiO2
Toyoda, T; Shen, Q; Hori, K; Nakazawa, N; Kamiyama, K; Hayase, S
Journal of Physical Chemistry C, 122, p.13590-13599, 2018., ACS, 122, 13590-13599, 2018, Peer-reviwed
Scientific journal, English

First-principles study of electronic and optical properties of lead-free double perovskites Cs2NaBX6 (B = Sb, Bi; X = Cl, Br, I)
Zhao, S; Yamamoto, K; Iikubo, S; Hayase, S., Ma
Journal of Physics and Chemistry of Solids, 117, 117-121, 2018, Peer-reviwed
Scientific journal, English

Implications of doping and depletion on the switching characteristics in polymer-based organic field-effect transistors
Tiwari, S; Pandey, M; Takashima, W; Nagamatsu, S; Balasubramanian, S.K; Hayase, S; Pandey, S.S; Prakash, R
Organic Electronics: physics, materials, applications, Elsevier, 56, 152-158, 2018, Peer-reviwed
Scientific journal, English

Journal of Physical Chemistry Letters
Ito, N; Kamarudin, M.A; Hirotani, D; Zhang, Y; Shen, Q; Ogomi, Y; Iikubo, S; Minemoto, T; Yoshino, K; Hayase, S
Mixed Sn-Ge Perovskite for Enhanced Perovskite Solar Cell Performance in Air, ACS, 9, 1682-1688, 2018, Peer-reviwed
Scientific journal, English

Interparticle coupling effect of silver-gold heterodimer to enhance light harvesting in ultrathin perovskite solar cell
Zhaosheng Hu; Tingli Ma; Shuzi Hayase
Journal of Photonics for Energy, SPIE, 8, 1, 15502, 01 Jan. 2018, Peer-reviwed
Scientific journal, English

Enhanced performance of ZnO based perovskite solar cells by Nb2O5 surface passivation
Zhang, P; Yang, F; Kapil, G; Shen, Q; Toyoda, T; Yoshino, K; Minemoto, T; Pandey, S.S; Ma, T; Hayase, S
Organic Electronics: physics, materials, applications, 62, 615-620, 2018, Peer-reviwed
Scientific journal, English

Structural Stability of Iodide Perovskite: A Combined Cluster Expansion Method and First-Principles Study
K. Yamamoto; S. Iikubo; J. Yamasaki; Y. Ogomi; S. Hayase
Journal of Physical Chemistry C, American Chemical Society, 121, 50, 27797-27804, 21 Dec. 2017
Scientific journal, English

Casting Control of Floating-films into Ribbon-shape Structure by modified Dynamic FTM
A Tripathi; M Pandey; S Nagamatsu; S S Pandey; S Hayase; W Takashima
Journal of Physics: Conference Series, {IOP} Publishing, 924, 012014-012014, Nov. 2017, Peer-reviwed
Scientific journal

Colloidal Synthesis of Air-Stable Alloyed CsSn1-xPxI3 Perovskite Nanocrystals for Use in Solar Cells
Feng Liu; Chao Ding; Yaohong Zhang; Teresa S. Ripolles; Taichi Kamisaka; Taro Toyoda; Shuzi Hayase; Takashi Minemoto; Kenji Yoshino; Songyuan Dai; Masatoshi Yanagida; Hidenori Noguchi; Qing Shen
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 139, 46, 16708-16719, Nov. 2017, Peer-reviwed, True
Scientific journal, English

Dependences of the Optical Absorption, Ground State Energy Level, and Interfacial Electron Transfer Dynamics on the Size of CdSe Quantum Dots Adsorbed on the (001), (110), and (111) Surfaces of Single Crystal Rutile TiO2
Taro Toyoda; Qing Shen; Keita Kamiyama; Kenji Katayama; Shuzi Hayase
JOURNAL OF PHYSICAL CHEMISTRY C, 121, 45, 25390-25401, Nov. 2017, Peer-reviwed
Scientific journal, English

Investigation of the minimum driving force for dye regeneration utilizing model squaraine dyes for dye-sensitized solar cells
Anusha Pradhan; Takuya Morimoto; Maryala Saikiran; Gaurav Kapil; Shuzi Hayase; Shyam S. Pandey
JOURNAL OF MATERIALS CHEMISTRY A, 5, 43, 22672-22682, Nov. 2017, Peer-reviwed
Scientific journal, English

Origin of Open Circuit Voltage in wide band gap absorbers of all inorganic Cesium Perovskite Solar Cells
Teresa S. Ripolles; Chi Huey Ng; Kengo Hamada; Siow Hwa Teo; Hong Ngee Lim; Juan Bisquert; Shuzi Hayase
Proceedings of the 2nd Asia-Pacific Hybrid and Organic Photovoltaics, Fundació Scito, 27 Oct. 2017
International conference proceedings

Study to realize the effect of multiple monovalent cation for lead/tin mixed perovskite solar cells
Gaurav Kapil; Kengo Hamada; Yuhei Ogomi; Takeru Bessho; Takumi Kinoshita; Qing Shen; Taro Toyoda; Takurou N Murakami; Hiroshi Segawa; Shuzi Hayase
Proceedings of the 2nd Asia-Pacific Hybrid and Organic Photovoltaics, Fundació Scito, 27 Oct. 2017
International conference proceedings

Highly Luminescent Phase-Stable CsPbl(3) Perovskite Quantum Dots Achieving Near 100% Absolute Photoluminescence Quantum Yield
Feng Liu; Yaohong Zhang; Chao Ding; Syuusuke Kobayashi; Takuya Izuishi; Naoki Nakazawa; Taro Toyoda; Tsuyoshi Ohta; Shuzi Hayase; Takashi Minemoto; Kenji Yoshino; Songyuan Dai; Qing Shen
ACS NANO, 11, 10, 10373-10383, Oct. 2017, Peer-reviwed, True
Scientific journal, English

Slow hot carrier cooling in cesium lead iodide perovskites
Qing Shen; Teresa S. Ripolles; Jacky Even; Yuhei Ogomi; Koji Nishinaka; Takuya Izuishi; Naoki Nakazawa; Yaohong Zhang; Chao Ding; Feng Liu; Taro Toyoda; Kenji Yoshino; Takashi Minemoto; Kenji Katayama; Shuzi Hayase
APPLIED PHYSICS LETTERS, 111, 15, Oct. 2017, Peer-reviwed
Scientific journal, English

Enhancement of efficiency for mixed metal Sn/Pb perovskite solar cells from the view point of hetero-interface traps (Conference Presentation)
Yuhei Ogomi; Daiki Yamasuso; Ayumu Yonaha; Kengo Hamada; Erina Yamaguchi; Qing Shen; Taro Toyoda; Kenji Yoshino; Takashi Minemoto; Shuzi Hayase
Organic, Hybrid, and Perovskite Photovoltaics XVIII, SPIE, 34-34, 19 Sep. 2017
International conference proceedings

Efficient near infrared fluorescence detection of elastase enzyme using peptide-bound unsymmetrical squaraine dye
Maryala Saikiran; Daisuke Sato; Shyam S. Pandey; Shuzi Hayase; Tamaki Kato
BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, 27, 17, 4024-4029, Sep. 2017, Peer-reviwed, True
Scientific journal, English

Current Advancements in Material Research and Techniques Focusing on Lead-free Perovskite Solar Cells
Chu Zhang; Liguo Gao; Shuzi Hayase; Tingli Ma
CHEMISTRY LETTERS, 46, 9, 1276-1284, Sep. 2017
English

In Situ Fabrication of Integrated Electrode of Perovskite Solar Cells
Liguo Gao; Shuzhang Yang; Yanqiang Li; Erling Zhao; Likun Wang; Chuanlei Fu; Shuzi Hayase; Tingli Ma
CHEMISTRY LETTERS, 46, 11, 1687-1690, Sep. 2017
Scientific journal, English

In Situ Fabrication of Nanoepitaxial TiO2 Protection Layer on Si Substrate: Hole Chemical Conduction Instead of Tunneling Effect
Liguo Gao; Qun Li; Hanlin Chen; Shuji Hayase; Tingli Ma
Solar RRL, Wiley-VCH Verlag, 1, 8, 01 Aug. 2017
Scientific journal, English

Improved Reproducibility and Intercalation Control of Efficient Planar Inorganic Perovskite Solar Cells by Simple Alternate Vacuum Deposition of PbI2 and CsI
Md. Shahiduzzaman; Kyosuke Yonezawa; Kohei Yamamoto; Teresa S. Ripolles; Makoto Karakawa; Takayuki Kuwabara; Kohshin Takahashi; Shuzi Hayase; Tetsuya Taima
ACS Omega, American Chemical Society ({ACS}), 2, 8, 4464-4469, Aug. 2017, Peer-reviwed, True, Vacuum deposition is a simple and controllable approach that aims to form higher-quality perovskite films compared with those formed using solution-based deposition processes. Herein, we demonstrate a novel method to promote the intercalation control of inorganic cesium lead iodide (CsPbI3) perovskite thin films via alternate vacuum deposition. We also investigated the effect of layer-by-layer deposition of PbI2/CsI to fabricate efficient planar heterojunction CsPbI3 thin films and solar cells. This procedure is comparatively simple when compared with commonly used coevaporation techniques; further, precise intercalation control of the CsPbI3 thin films can be achieved by increasing the number of layers in the layer-by-layer deposition of PbI2/CsI. The best control and the highest reproducibility were achieved for the deposition of four double layers owing to the precise intercalation control during the deposition of the CsPbI3 thin film. A power conversion efficiency of 6.79% was obtained via alternating vacuum deposition of two double layers with a short-circuit current density (J sc) of 12.06 mA/cm2, an open-circuit voltage (V oc) of 0.79 V, and a fill factor (FF) of 0.72. Our results suggest a route for inorganic precursors to be used for efficient perovskite solar cells via alternating vacuum deposition.
Scientific journal, English

Transparent Conductive Oxide-Less Dye-Sensitized Solar Cells Consisting of Dye-Cocktail and Cobalt Based Redox Electrolyte
Md. Zaman Molla; Ajay K. Baranwal; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 17, 7, 4748-4754, Jul. 2017
Scientific journal, English

Investigation of Interfacial Charge Transfer in Solution Processed Cs2SnI6 Thin Films
Gaurav Kapil; Ttakeshi Ohta; Tsuguo Koyanagi; Murugan Vigneshwaran; Yaohong Zhang; Yuhei Ogomi; Shyam S. Pandey; Kenji Yoshino; Qing Shen; Taro Toyoda; Md. Mijanur Rahman; Takashi Minemoto; Takurou N. Murakami; Hiroshi Segawa; Shuzi Hayase
JOURNAL OF PHYSICAL CHEMISTRY C, 121, 24, 13092-13100, Jun. 2017, Peer-reviwed
Scientific journal, English

Interplay of Orientation and Blending: Synergistic Enhancement of Field Effect Mobility in Thiophene-Based Conjugated Polymers
Manish Pandey; Shuichi Nagamatsu; Wataru Takashima; Shyam S. Pandey; Shuzi Hayase
JOURNAL OF PHYSICAL CHEMISTRY C, 121, 21, 11184-11193, Jun. 2017, Peer-reviwed
Scientific journal, English

Atmospheric growth of ZnO films deposited by spray pyrolysis using diethylzinc solution
Masato Imai; Marin Watanabe; Akiko Mochihara; Himeka Tominaga; Kenji Yoshino; Qing Shen; Taro Toyoda; Shuzi Hayase
JOURNAL OF CRYSTAL GROWTH, 468, 473-476, Jun. 2017, Peer-reviwed
Scientific journal, English

Photophysical characterization and BSA interaction of the direct ring carboxy functionalized unsymmetrical NIR cyanine dyes
Maryala Saikiran; Daisuke Sato; Shyam S. Pandey; Takeshi Ohta; Shuzi Hayase; Tamaki Kato
DYES AND PIGMENTS, 140, 6-13, May 2017, Peer-reviwed
Scientific journal, English

Layer-by-layer coating of oriented conjugated polymer films towards anisotropic electronics
Manish Pandey; Shifumi Sadakata; Shuichi Nagamatsu; Shyam S. Pandey; Shuzi Hayase; Wataru Takashima
SYNTHETIC METALS, 227, 29-36, May 2017, Peer-reviwed
Scientific journal, English

Improvement of Photovoltaic Performance of Colloidal Quantum Dot Solar Cells Using Organic Small Molecule as Hole-Selective Layer
Yaohong Zhang; Guohua Wu; Ivan Mora-Sero; Chao Ding; Feng Liu; Qingxun Huang; Yuhei Ogomi; Shuzi Hayase; Taro Toyoda; Ruixiang Wang; Joe Otsuki; Qing Shen
JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 8, 10, 2163-2169, May 2017, Peer-reviwed, True
Scientific journal, English

Solvent driven performance in thin floating-films of PBITT for organic field effect transistor: Role of macroscopic orientation
Manish Pandey; Shyam S. Pandey; Shuichi Nagamatsu; Shuzi Hayase; Wataru Takashima
ORGANIC ELECTRONICS, 43, 240-246, Apr. 2017, Peer-reviwed
Scientific journal, English

Effect of lead-free (CH3NH3)(3)Bi2I9 perovskite addition on spectrum absorption and enhanced photovoltaic performance of bismuth triiodide solar cells
Chunfeng Lan; Jingting Luo; Shuai Zhao; Chu Zhang; Weiguo Liu; Shuzi Hayase; Tingli Ma
JOURNAL OF ALLOYS AND COMPOUNDS, 701, 834-840, Apr. 2017
Scientific journal, English

Annealing effects on CsPbI3-based planar heterojunction perovskite solar cells formed by vacuum deposition method
Kyosuke Yonezawa; Kohei Yamamoto; Md. Shahiduzzaman; Yoshikazu Furumoto; Keitaro Hamada; Teresa S. Ripolles; Makoto Karakawa; Takayuki Kuwabara; Kohshin Takahashi; Shuzi Hayase; Tetsuya Taima
JAPANESE JOURNAL OF APPLIED PHYSICS, 56, 4, Apr. 2017, Peer-reviwed
Scientific journal, English

Annealing effects on CsPbI
Yonezawa Kyosuke; Yamamoto Kohei; Shahiduzzaman Md.; Furumoto Yoshikazu; Hamada Keitaro; Ripolles Teresa; Karakawa Makoto; Kuwabara Takayuki; Takahashi Kohshin; Hayase Shuzi; Taima Tetsuya
Jpn. J. Appl. Phys., Institute of Physics, 56, 4, 04CS11, 24 Mar. 2017, Cesium iodide (CsI) is attracting attention as a substitute for organic materials such as CH3NH3I. In this work, we fabricated sequential-vacuum-deposited planar heterojunction (PHJ) cesium lead iodide (CsPbI3) perovskite solar cells with enhanced efficiencies by varying the annealing time (0.5, 1, 5, and 10 min). The effect of performance enhancement was investigated as a function of varying annealing time at 350 °C employing a hot plate. The best-performing device was obtained with an annealing time of 1 min, delivered photocurrent density (JSC) of 12.06 mA/cm², voltage (VOC) of 0.71 V, and fill factor (FF) of 0.67, leading to a power conversion efficiency (PCE) of 5.71% at standard AM 1.5G solar illumination.
English

Ligand-dependent exciton dynamics and photovoltaic properties of PbS quantum dot heterojunction solar cells
Jin Chang; Yuhei Ogomi; Chao Ding; Yao Hong Zhang; Taro Toyoda; Shuzi Hayase; Kenji Katayama; Qing Shen
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 19, 9, 6358-6367, Mar. 2017, Peer-reviwed, True
Scientific journal, English

Controlling Factors for Orientation of Conjugated Polymer Films in Dynamic Floating-Film Transfer Method
Manish Pandey; Shyam S. Pandey; Shuichi Nagamatsu; Shuzi Hayase; Wataru Takashima
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 17, 3, 1915-1922, Mar. 2017, Peer-reviwed
Scientific journal, English

Transparent Conductive Oxide Layer and Hole Selective Layer Free Back-Contacted Hybrid Perovskite Solar Cell
Zhaosheng Hu; Gaurav Kapil; Hiromitsu Shimazaki; Shyam Sudhir Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF PHYSICAL CHEMISTRY C, 121, 8, 4214-4219, Mar. 2017
Scientific journal, English

Photovoltaic Properties of CdSe Quantum Dot Sensitized Inverse Opal TiO2 Solar Cells: The Effect of TiCl4 Post Treatment
Motoki Hironaka; Taro Toyoda; Kanae Hori; Yuhei Ogomi; Shuzi Hayase; Qing Shen
Journal of Modern Physics, 8, 522-530, 2017, Peer-reviwed
Scientific journal, English

Research following Pb Perovskite Solar Cells
HAYASE Shuzi
Electrochemistry, The Electrochemical Society of Japan, 85, 5, 222-225, 2017, Certified efficiency of Pb perovskite solar cells with mixed cations is reported to be 19.6% (1 cm²). One of the recent research interests is on enhancing the solar cell efficiency further. Band gap of the present Pb perovskite is about 1.55 eV. Supposing that Voc loss is 0.4 eV, the best efficiency is obtained by using perovskite with about 1.4 eV band gap. One of the candidates for the narrow band gap perovskite material is SnPb mixed metal perovskite. In this paper, the relationship between Voc losses and hetero-interface structures is discussed in detail, leading to the conclusion that hetero-interface structures give serious effects on the solar cell efficiency. It is reported that the efficiency was enhanced from about 5% to 16% after optimization of the hetero-interface structure. In addition, research trend on Pb free perovskite solar cells consisting of Sn or Bi, which is another recent research interest, is also reviewed.
English

Combined theoretical and experimental approaches for development of squaraine dyes with small energy barrier for electron injection
Shyam S. Pandey; Takuya Morimoto; Naotaka Fujikawa; Shuzi Hayase
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 159, 625-632, Jan. 2017, Peer-reviwed
Scientific journal, English

Transparent conductive oxide-less back contact dye-sensitized solar cells using flat titanium sheet with microholes for photoanode fabrication
Azwar Hayat; Ajay Kumar Baranwal; Masaki Nakamura; Fujisawa Shigeki; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF PHOTONICS FOR ENERGY, 7, 1, Jan. 2017
Scientific journal, English

Air Stable PbSe Colloidal Quantum Dot Heterojunction Solar Cells: Ligand-Dependent Exciton Dissociation, Recombination, Photovoltaic Property, and Stability
Yaohong Zhang; Chao Ding; Guohua Wu; Naoki Nakazawa; Jin Chang; Yuhei Ogomi; Taro Toyoda; Shuzi Hayase; Kenji Katayama; Qing Shen
JOURNAL OF PHYSICAL CHEMISTRY C, 120, 50, 28509-28518, Dec. 2016, Peer-reviwed
Scientific journal, English

Influence of backbone structure on orientation of conjugated polymers in the dynamic casting of thin floating-films
Manish Pandey; Shyam S. Pandey; Shuichi Nagamatsu; Shuzi Hayase; Wataru Takashima
THIN SOLID FILMS, 619, 125-130, Nov. 2016, Peer-reviwed
Scientific journal, English

Enhancement of carrier mobility along with anisotropic transport in non-regiocontrolled poly (3-hexylthiophene) films processed by floating film transfer method
Manish Pandey; Shuichi Nagamatsu; Shyam S. Pandey; Shuzi Hayase; Wataru Takashima
ORGANIC ELECTRONICS, 38, 115-120, Nov. 2016, Peer-reviwed
Scientific journal, English

The effect of CdS on the charge separation and recombination dynamics in PbS/CdS double-layered quantum dot sensitized solar cells
Koki Sato; Keita Ono; Takuya Izuishi; Shota Kuwahara; Kenji Katayama; Taro Toyoda; Shuzi Hayase; Qing Shen
CHEMICAL PHYSICS, 478, 159-163, Oct. 2016, Peer-reviwed
Scientific journal, English

Architecture of the Interface between the Perovskite and Hole-Transport Layers in Perovskite Solar Cells.
Masahiro Moriya; Daisuke Hirotani; Tsuyoshi Ohta; Yuhei Ogomi; Qing Shen; Teresa S Ripolles; Kenji Yoshino; Taro Toyoda; Takashi Minemoto; Shuzi Hayase
ChemSusChem, ChemSusChem, 9, 18, 2634-2639, 22 Sep. 2016, True, The interface between the perovskite (PVK, CH3 NH3 PbI3 ) and hole-transport layers in perovskite solar cells is discussed. The device architecture studied is as follows: F-doped tin oxide (FTO)-coated glass/compact TiO2 /mesoporous TiO2 /PVK/2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-MeOTAD)/Au. After a thin layer of 4,4,4-trifluorobutylammonium iodide (TFBA) was inserted at the interface between PVK and Spiro-MeOTAD, the photovoltaic efficiency increased from 11.6-14.5 % to 15.1-17.6 %. TFBA (10 ppm) was added in the PVK solution before coating. Owing to the low surface tension of TFBA, TFBA rose to the surface of the PVK layer spontaneously during spin-coating to make a thin organic layer. The PVK grain boundaries also seemed to be passivated with the addition of TFBA. However, large differences in Urbach energies and valence band energy level were not observed for the PVK layer with and without the addition of TFBA. The charge recombination time constant between the PVK and the Spiro-MeOTAD became slower (from 8.4 to 280 μsec) after 10 ppm of TFBA was added in the PVK. The experimental results using TFBA conclude that insertion of a very thin layer at the interface between PVK and Spiro-MeOTAD is effective for suppressing charge recombination and increasing photovoltaic performances.
Scientific journal, Japanese

Adsorption and Electronic Structure of CdSe Quantum Dots on Single Crystal ZnO: A Basic Study of Quantum Dot-Sensitization System
Taro Toyoda; Witoon Yindeesuk; Keita Kamiyama; Shuzi Hayase; Qing Shen
JOURNAL OF PHYSICAL CHEMISTRY C, 120, 30, 16367-16376, Aug. 2016, Peer-reviwed
Scientific journal, English

Mechanisms of charge accumulation in the dark operation of perovskite solar cells
Teresa S. Ripolles; Ajay K. Baranwal; Koji Nishinaka; Yuhei Ogomi; Germa Garcia-Belmonte; Shuzi Hayase
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 18, 22, 14970-14975, Jun. 2016, Peer-reviwed
Scientific journal, English

Effect of Addition of KI on the Hydrothermal Growth of ZnO Nanostructures Towards Hybrid Optoelectronic Device Applications
Anubha Bilgaiyan; Tejendra Dixit; Gaurav Kapil; Shyam S. Pandey; Shuji Hayase; Iyamperumal Anand Palani; Vipul Singh
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 16, 4, 3301-3306, Apr. 2016, Peer-reviwed
Scientific journal, English

Design of Far-Red Sensitizing Squaraine Dyes Aiming Towards the Fine Tuning of Dye Molecular Structure
Takuya Morimoto; Naotaka Fujikawa; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 16, 4, 3282-3288, Apr. 2016
Scientific journal, English

Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells
Gaurav Kapil; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, 16, 4, 3183-3187, Apr. 2016
Scientific journal, English

Low-temperature Growth of Porous and Dense ZnO Films for Perovskite Solar Cells on ITO Substrate
Kenji Yoshino; Akiko Ide; Akiko Mochihara; Yuhei Ogomi; Qing Shen; Taro Toyoda; Shuzi Hayase
CHEMISTRY LETTERS, 45, 2, 176-178, Feb. 2016, Peer-reviwed
Scientific journal, English

The Electronic Structure and Photoinduced Electron Transfer Rate of CdSe Quantum Dots on Single Crystal Rutile TiO2: Dependence on the Crystal Orientation of the Substrate
Taro Toyoda; Witoon Yindeesuk; Keita Karniyama; Kenji Katayama; Hisayoshi Kobayashi; Shuzi Hayase; Qing Shen
JOURNAL OF PHYSICAL CHEMISTRY C, 120, 4, 2047-2057, Feb. 2016, Peer-reviwed
Scientific journal, English

Effect of Varying Alkyl Chain Length on Thermal Decomposition Temperature of Zinc(II) Xanthates and its Impact on Curing of Epoxy Resin
Tarun Chand Vagvala; Shyam Sudhir Pandey; Suvratha Krishnamurthy; Shuzi Hayase
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE, 642, 2, 134-139, Jan. 2016, Peer-reviwed
Scientific journal, English

Orientation Characteristics of Non-regiocontrolled Poly(3-hexyl-thiophene) Film by FTM on Various Liquid Substrates
M. Pandey; S. Nagamatsu; S. S. Pandey; S. Hayase; W. Takashima
INDIA-JAPAN EXPERT GROUP MEETING ON BIOMOLECULAR ELECTRONICS & ORGANIC NANOTECHNOLOGY FOR ENVIRONMENT PRESERVATION (IJEGMBE 2015), 704, 012005-1-012005-7, 2016, Peer-reviwed
International conference proceedings, English

Parametric Optimization of Experimental Conditions for Dye-Sensitized Solar Cells based on Far-red Sensitive Squaraine Dye
Takuya Morimoto; Naotaka Fujikawa; Yuhei Ogomi; Shyam S. Pandey; Shuzi Hayase
INDIA-JAPAN EXPERT GROUP MEETING ON BIOMOLECULAR ELECTRONICS & ORGANIC NANOTECHNOLOGY FOR ENVIRONMENT PRESERVATION (IJEGMBE 2015), 704, 0120021-0120027, 2016, Peer-reviwed
Scientific journal, English

Tandem Dye-Sensitized Solar Cells Based on TCO-less Back Contact Bottom Electrodes
Ajay K. Baranwal; Naotaka Fujikawa; Terumi Nishimura; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
INDIA-JAPAN EXPERT GROUP MEETING ON BIOMOLECULAR ELECTRONICS & ORGANIC NANOTECHNOLOGY FOR ENVIRONMENT PRESERVATION (IJEGMBE 2015), 704, 1, 2016
International conference proceedings, English

First principles analysis of oxygen vacancy formation and migration in Sr2BMoO6 (B = Mg, Co, Ni)
Shuai Zhao; Liguo Gao; Chunfeng Lan; Shyam S. Pandey; Shuzi Hayase; Tingli Ma
RSC ADVANCES, 6, 38, 31968-31975, 2016
Scientific journal, English

Enhancing the performance of transparent conductive oxide-less back contact dye-sensitized solar cells by facile diffusion of cobalt species through TiO2 nanopores
Md. Zaman Molla; Minobu Kawano; Ajay K. Baranwal; Shyam S. Pandey; Yuhei Ogomi; Tingli Ma; Shuzi Hayase
RSC ADVANCES, 6, 40, 33353-33360, 2016
Scientific journal, English

Near IR sensitive Sn based perovskite solar cells with high current density reaching 30mA/cm(2)
Yuhei Ogomi; Daisuke Hirotani; Kosei Fujiwara; Keita Sakaguchi; Qing Shen; Taro Toyoda; Kenji Yoshino; Atsushi Wakamiya; Teresa S. Ripolles; Shuzi Hayase
2016 IEEE 43RD PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC), 808-811, 2016, Peer-reviwed
International conference proceedings, English

Concentration gradient controlled growth of large-grain CH3NH3PbI3 films and enhanced photovoltaic performance of solar cells in ambient conditions.
Chunfeng Lan; Shuai Zhao; Chu Zhang; Weiguo Liu; Shuzi Hayase; Tingli Ma
CrystEngComm, 18, 48, 9243-9251, 2016

Oxygen vacancy formation and migration in double perovskite Sr2CrMoO6: a first-principles study.
Shuai Zhao; Liguo Gao; Chunfeng Lan; Shyam S. Pandey; Shuzi Hayase; Tingli Ma
RSC Advances, 2016, 49, 43034-43040, 2016
Scientific journal, English

Investigation on structures, band gaps, and electronic structures of lead free La2NiMnO6 double perovskite materials for potential application of solar cell.
Chunfeng Lan; Shuai Zhao; Tingting Xu; Jie Ma; Shuzi Hayase; Tingli Ma
Journal of Alloys and Compounds, 655, 208-214, 2016

Uncovering the charge transfer and recombination mechanism in ZnS-coated PbS quantum dot sensitized solar cells
Jin Chang; Takuya Oshima; Sojiro Hachiya; Konki Sato; Taro Toyoda; Kenji Katayama; Shuzi Hayase; Qing Shen
SOLAR ENERGY, 122, 307-313, Dec. 2015, Peer-reviwed
Scientific journal, English

Effects of different chloride precursors on crystal growth of lead halide perovskites
Vigneshwaran Murugan; Yuhei Ogomi; Shyam S. Pandey; Taro Toyoda; Qing Shen; Shuzi Hayase
APPLIED PHYSICS EXPRESS, 8, 12, Dec. 2015, Peer-reviwed
Scientific journal, English

Transparent conductive oxide-less back contact dye-sensitized solar cells using cobalt electrolyte
Md. Zaman Molla; Norihiro Mizukoshi; Hiroaki Furukawa; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
PROGRESS IN PHOTOVOLTAICS, 23, 9, 1100-1109, Sep. 2015
Scientific journal, English

Investigation of metal xanthates as latent curing catalysts for epoxy resin via formation of in-situ metal sulfides
Tarun Chand Vagvala; Shyam Sudhir Pandey; Yuhei Ogomi; Tingly Ma; Shuzi Hayase
INORGANICA CHIMICA ACTA, 435, 292-298, Aug. 2015, Peer-reviwed
Scientific journal, English

Effect of defects in TiO2 nanotube thin film on the photovoltaic properties of quantum dot-sensitized solar cells
Masaya Akimoto; Taro Toyoda; Tsuyoshi Okuno; Shuzi Hayase; Qing Shen
Thin Solid Films, Elsevier, 590, 90-97, 21 Jul. 2015, Peer-reviwed
Scientific journal, English

Nonisothermal curing kinetics of epoxy resin composite utilizing Ga (III) xanthate as a latent catalyst
Tarun Chand Vagvala; Gaurav Kapil; Shyam S. Pandey; Yuhei Ogomi; Shuzi Hayase
JOURNAL OF APPLIED POLYMER SCIENCE, 132, 26, Jul. 2015, Peer-reviwed
Scientific journal, English

Simple Metal-Free Dyes Derived from Triphenylamine for DSSC: A Comparative Study of Two Different Anchoring Group
K. Narayanaswamy; T. Swetha; Gaurav Kapil; Shyam S. Pandey; Shuzi Hayase; Surya Prakash Singh
ELECTROCHIMICA ACTA, 169, 256-263, Jul. 2015, Peer-reviwed
Scientific journal, English

First principles study on the electronic and optical properties of B-site ordered double perovskite Sr2MMoO6 (M=Mg, Ca, and Zn)
Shuai Zhao; Chunfeng Lan; Jie Ma; Shyam S. Pandey; Shuzi Hayase; Tingli Ma
SOLID STATE COMMUNICATIONS, 213, 19-23, Jul. 2015
Scientific journal, English

Dye-sensitized solar cells based on axially ligated phosphorus-phthalocyanine dyes
Azwar Hayat; Gururaj M. Shivashimpi; Terumi Nishimura; Naotaka Fujikawa; Yuhei Ogomi; Yoshihiro Yamaguchi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
APPLIED PHYSICS EXPRESS, 8, 4, Apr. 2015
Scientific journal, English

Electronic structures of two types of TiO2 electrodes: inverse opal and nanoparticulate cases
Taro Toyoda; Witoon Yindeesuk; Tsuyoshi Okuno; Masaya Akimoto; Keita Kamiyama; Shuzi Hayase; Qing Shen
RSC ADVANCES, 5, 61, 49623-49632, 2015, Peer-reviwed
Scientific journal, English

High reduction of interfacial charge recombination in colloidal quantum dot solar cells by metal oxide surface passivation
Jin Chang; Yuki Kuga; Ivan Mora-Sero; Taro Toyoda; Yuhei Ogomi; Shuzi Hayase; Juan Bisquert; Qing Shen
NANOSCALE, 7, 12, 5446-5456, 2015, Peer-reviwed
Scientific journal, English

Optical absorption, charge separation and recombination dynamics in Sn/Pb cocktail perovskite solar cells and their relationships to photovoltaic performances
Qing Shen; Yuhei Ogomi; Jin Chang; Taro Toyoda; Kosei Fujiwara; Kenji Yoshino; Koki Sato; Kohei Yamazaki; Masaya Akimoto; Yuki Kuga; Kenji Katayama; Shuzi Hayase
JOURNAL OF MATERIALS CHEMISTRY A, 3, 17, 9308-9316, 2015, Peer-reviwed
Scientific journal, English

Infrared light sensitive Sn/Pb binary perovskite solar cells with improved stability in air and organic amine-free perovskite solar cells with improved stability against light exposure
Yuhei Ogomi; Qing Shen; Koji Nishinaka; Teresa S. Ripolles; Kosei Fujiwara; Keita Sakaguchi; Taro Toyoda; Shuzi Hayase
2015 IEEE 42ND PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC), 2015, Peer-reviwed
International conference proceedings, English

Relationship between diffusion of Co3+/Co2+ redox species in nanopores of porous titania stained with dye molecules, dye molecular structures, and photovoltaic performances
Minobu Kawano; Tsubasa Nishiyama; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
RSC ADVANCES, 5, 102, 83725-83731, 2015
Scientific journal, English

Combining novel device architecture and NIR dye towards the fabrication of transparent conductive oxide-less tandem dye sensitized solar cells
Ajay Kumar Baranwal; Naotaka Fujikawa; Azwar Hayat; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
Applied Physics Express, Institute of Physics, 10, 8, 102301-102301, 2015, Tandem solar cells with different device architectures utilizing a back contact transparent conductive oxide-less bottom electrode (TCO-less tandem DSSC) that has better control of the optical transmission losses incurred by intermediate TCO layers with flexible Pt/tin-doped indium oxide (ITO)-polyethylene terephthalate film as an intermediate layer are reported. The proposed device architecture suppresses the optical loss to a greater extent (around 30%). Sensitizers were ruthenium-based N719 dye in the top electrode, while the newly synthesized phthalocyanine dye (PC25) corresponding to photon harvesting in the near infrared (NIR) region (up to 900 nm) was used in the TCO-less bottom cell. Open circuit voltage (Voc) ≥ 1.18 V (sum of top cell and bottom cell Voc) justifies the TCO-less tandem DSSC formation.
English

Complete Photodynamics of the Efficient YD2-o-C8 Based Solar Cell
Piotr Piatkowski; Cristina Martin; Maria Rosaria di Nunzio; Boiko Cohen; Shyam S Pandey; Shuzi Hayase; Abderrazzak Douhal
Journal of Physical Chemistry C, -sspandey, Nov. 2014, Peer-reviwed
Scientific journal, English

Titanium wire engineering and its effect on the performance of coil type cylindrical dye sensitized solar cells
Gaurav Kapil; Shyam S. Pandey; Yuhei Ogomi; Tingli Ma; Shuzi Hayase
ORGANIC ELECTRONICS, 15, 11, 3399-3405, Nov. 2014
Scientific journal, English

Template-Assisted Electrochemical Growth of Polypyrrole Nanotubes for Development of High Sensitivity Glucose Biosensor
Pragya Agar Palod; Shyam S. Pandey; Shuji Hayase; Vipul Singh
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY, 174, 3, 1059-1072, Oct. 2014, Peer-reviwed
Scientific journal, English

Graphene Oxide-Based Biosensor for Food Toxin Detection
Saurabh Srivastava; Md Azahar Ali; Sima Umrao; Upendra Kumar Parashar; Anchal Srivastava; Gajjala Sumana; B. D. Malhotra; Shyam Sudhir Pandey; Shuji Hayase
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY, 174, 3, 960-970, Oct. 2014, Peer-reviwed
Scientific journal, English

Improved Understanding of the Electronic and Energetic Landscapes of Perovskite Solar Cells: High Local Charge Carrier Mobility, Reduced Recombination, and Extremely Shallow Traps
Hikaru Oga; Akinori Saeki; Yuhei Ogomi; Shuzi Hayase; Shu Seki
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 136, 39, 13818-13825, Oct. 2014, Peer-reviwed
Scientific journal, English

Far-red sensitizing octatrifluorobutoxy phosphorous triazatetrabenzocorrole: Synthesis, spectral characterization and aggregation studies
Gururaj M. Shivashimpi; Shyam S. Pandey; Azwar Hayat; Naotaka Fujikawa; Yuhei Ogomi; Yoshihiro Yamaguchi; Shuzi Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 289, 53-59, Sep. 2014, Peer-reviwed
Scientific journal, English

Molecular Structure and Crystal Packing of n-Type Semiconducting Material 3',3'-(1,4-Phenylene) bis {2'-(4-trifluoromethyl) phenyl} acrylonitrile
Moriguchi Tetsuji; Nagamatsu Shuichi; Okauchi Tatsuo; Tsuge Akihiko; Takashima Wataru; Hayase Shuji
Journal of Crystallography, Hindawi Publishing Corporation, 2014, 257249-1-257249-5, 19 Aug. 2014, The exact molecular structure and the crystal packing of the n-type semiconducting material 3′,3′-(1,4-phenylene)bis{2′-(4-trifluoromethyl)phenyl}acrylonitrile was determined by a single crystal X-ray diffraction with twin treatment technique. The air-stable product was crystallized from dichloromethane-hexane mixed solution. The solid-state structure is the example of a typical π-π stacking with side intermolecular CN–H short contact networks.
English

Effect of TiO2 Crystal Orientation on the Adsorption of CdSe Quantum Dots for Photosensitization Studied by the Photoacoustic and Photoelectron Yield Methods
Taro Toyoda; Witoon Yindeesuk; Keita Kamiyama; Shuzi Hayase; Qing Shen
JOURNAL OF PHYSICAL CHEMISTRY C, 118, 30, 16680-16687, Jul. 2014, Peer-reviwed
Scientific journal, English

Photoacoustic spectroscopy of TiO2 nanotube electrode adsorbed with CdSe quantum dots and its photovoltaic properties
Masaya Akimoto; Qing Shen; Shuji Hayase; Taro Toyoda
JAPANESE JOURNAL OF APPLIED PHYSICS, 53, 7, Jul. 2014, Peer-reviwed
Scientific journal, English

All-Solid Perovskite Solar Cells with HOCO-R-NH3+I- Anchor-Group Inserted between Porous Titania and Perovskite
Yuhei Ogomi; Atsushi Morita; Shota Tsukamoto; Takahiro Saitho; Qing Shen; Taro Toyoda; Kenji Yoshino; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF PHYSICAL CHEMISTRY C, 118, 30, 16651-16659, Jul. 2014
Scientific journal, English

Photoacoustic spectroscopy of TiO
Akimoto Masaya; Shen Qing; Hayase Shuji; Toyoda Taro
Jpn. J. Appl. Phys., Institute of Physics, 53, 7, 07KB08, 17 Jun. 2014
English

Reproducible Fabrication of Efficient Perovskite-based Solar Cells: X-ray Crystallographic Studies on the Formation of CH3NH3PbI3 Layers
Atsushi Wakamiya; Masaru Endo; Takahiro Sasamori; Norihiro Tokitoh; Yuhei Ogomi; Shuzi Hayase; Yasujiro Murata
CHEMISTRY LETTERS, 43, 5, 711-713, May 2014, Peer-reviwed
Scientific journal, English

Control of Charge Dynamics through a Charge-Separation Interface for All-Solid Perovskite-Sensitized Solar Cells
Yuhei Ogomi; Kenji Kukihara; Shen Qing; Taro Toyoda; Kenji Yoshino; Shyam Pandey; Hisayo Momose; Shuzi Hayase
CHEMPHYSCHEM, 15, 6, 1062-1069, Apr. 2014, Peer-reviwed
Scientific journal, English

Long-Term Air-Stable n-Channel Organic Thin-Film Transistors Using 2, 5-Difluoro-1, 4-phenylene-bis {2-[4-(trifluoromethyl) phenyl] acrylonitrile}
Shuichi Nagamatsu; Shinya Oku; Kouji Kuramoto; Tetsuji Moriguchi; Wataru Takashima; Tatsuo Okauchi; Shuzi Hayase
ACS Applied Materials and Interfaces, 6, 6, 3847-3852, 12 Mar. 2014, Peer-reviwed, True
Scientific journal, English

CH3NH3SnxPb(1-x)I3 Perovskite Solar Cells Covering up to 1060 nm
Yuhei Ogomi; Atsushi Morita; Syota Tsukamoto; Takahiro Saitho; Naotaka Fujikawa; Qing Shen; Taro Toyoda; Kenji Yoshino; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 5, 6, 1004-1011, Mar. 2014
Scientific journal, English

Tandem dye-sensitized solar cells with a back-contact bottom electrode without a transparent conductive oxide layer
A. K. Baranwal; T. Shiki; Y. Ogomi; S. S. Pandey; T. Ma; S. Hayase
RSC ADVANCES, 4, 88, 47735-47742, 2014, Peer-reviwed
Scientific journal, English

Gallium(III) xanthate as a novel thermal latent curing agent for an epoxy resin composite
Tarun Chand Vagvala; Shyam Sudhir Pandey; Yuhei Ogomi; Shuzi Hayase
RSC ADVANCES, 4, 47, 24658-24661, 2014, Peer-reviwed
Scientific journal, English

Improved Understanding of the Electronic and Energetic Landscapes of Perovskite Solar Cells: High Local Charge Carrier Mobility, Reduced Recombination, and Extremely Shallow Traps (vol 136, pg 13818, 2014)
Oga Hikaru; Saeki Akinori; Ogomi Yuhei; Hayase Shuzi; Seki Shu
Journal of the American Chemical Society, 136, 48, 16948, 2014, Peer-reviwed

Inhomogeneous deactivation with UV excitation in submicron grains of lead iodide perovskite-based solar cell as revealed by femtosecond transient absorption microscopy
Tetsuro Katayama; Akira Jinno; Eisuke Takeuchi; Syoji Ito; Masaru Endo; Atsushi Wakamiya; Yasujiro Murata; Yuhei Ogomi; Shuji Hayase; Hiroshi Miyasaka
Chemistry Letters, 43, 10, 1656-1658, 2014
Scientific journal

Effect of nature of anchoring groups on photosensitization behavior in unsymmetrical squaraine dyes
Gururaj M. Shivashimpi; Shyam S. Pandey; Rie Watanabe; Naotaka Fujikawa; Yuhei Ogomi; Yoshihiro Yamaguchi; Shuzi Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 273, 1-7, Jan. 2014, Peer-reviwed
Scientific journal, English

Charge transfer and recombination at the metal oxide/CH3NH3PbClI2/spiro-OMeTAD interfaces: uncovering the detailed mechanism behind high efficiency solar cells
Qing Shen; Yuhei Ogomi; Jin Chang; Syota Tsukamoto; Kenji Kukihara; Takuya Oshima; Naoya Osada; Kenji Yoshino; Kenji Katayama; Taro Toyoda; Shuzi Hayase
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 16, 37, 19984-19992, 2014, Peer-reviwed
Scientific journal, English

Low Temperature TiOx Compact Layer by Chemical Bath Deposition Method for Vapor Deposited Perovskite Solar cells.
Kouhei Yamamoto; Ying Zhou; Takayuki Kuwabara; Koshin Takahashi; Masaru Endo; Atushi Wakamiya; Yuhei Ogomi; Shuzi Hayase; Tetsuya Taima
2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC), 1573-1576, 2014, Peer-reviwed
International conference proceedings, English

All-solid Sn/Pb halide perovskite sensitized solar cells
Yuhei Ogomi; Atsushi Morital; Shota Tsukamotol; Takahiro Saithol; Naotaka Fujikawal; Shen Qing; Taro Toyoda; Kenji Yoshino; Shyam S. Pandeyl; Tingli Mal; Shuzi Hayase
2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC), 147-151, 2014, Peer-reviwed
International conference proceedings, English

Fabrication and characterization of coil type transparent conductive oxide-less cylindrical dye-sensitized solar cells
Gaurav Kapil; Jin Ohara; Yuhei Ogomi; Shyam S. Pandey; Tingli Ma; Shuzi Hayase
RSC ADVANCES, 4, 44, 22959-22963, 2014
Scientific journal, English

Transparent conductive oxide-less back contact dye-sensitized solar cells using Zinc porphyrin dye employing cobalt complex redox shuttle
Md. Zaman Molla; Shyam S. Pandey; Yuhei Ogomi; Tingli Ma; Shuzi Hayase
2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC), 1538-1542, 2014
International conference proceedings, English

Optical absorption of CdSe quantum dots on electrodes with different morphology
Witoon Yindeesuk; Qing Shen; Shuzi Hayase; Taro Toyoda
AIP ADVANCES, 3, 10, Oct. 2013, Peer-reviwed
Scientific journal, English

Huge Suppression of Charge Recombination in P3HT–ZnO Organic–Inorganic Hybrid Solar Cells by Locating Dyes at the ZnO/P3HT Interfaces
Qing Shen; Yuhei Ogomi; Sandeep K. Das; Shyam S. Pandey; Kenji Yoshino; Kenji Katayama; Hisayo Momose; Taro Toyoda; Shuzi Hayase
Phys. Chem. Chem. Phys., 15, 14370-14376, 01 Jul. 2013, Peer-reviwed
Scientific journal, English

Controlling the processable ZnO and polythiophene interface for dye-sensitized thin film organic solar cells
Sandeep K. Das; Katsunori Abe; Kenji Yoshino; Yuhei Ogomi; Shyam S. Pandey; Shuzi Hayase
Thin Solid Film, 536, 302-307, 01 Jul. 2013, Peer-reviwed
Scientific journal, English

Real-time photodynamics of squaraine-based dye-sensitized solar cells with iodide and cobalt electrolytes
María José Marchena; Gustavo De Miguel; Boiko Cohen; Juan Angel Organero; Shyam Pandey; Shuzi Hayase; Abderrazzak Douhal
Journal of Physical Chemistry C, 117, 23, 11906-11919, 13 Jun. 2013, Peer-reviwed
Scientific journal, English

Transparent conductive oxide-less three-dimensional cylindrical dye-sensitized solar cell fabricated with flexible metal mesh electrode
Jun Usagawa; Shyam S. Pandey; Yuhei Ogomi; Sho Noguchi; Yoshihiro Yamaguchi; Shuzi Hayase
Progress in Photovoltaics: Research and Applications, 21, 4, 517-524, Jun. 2013, Peer-reviwed
Scientific journal, English

Single-step fabrication of all-solid dye-sensitized solar cells using solution-processable precursor
Sandeep K. Das; Daiki Yamashita; Yuhei Ogomi; Shyam S. Pandey; Kenji Yoshino; Shuzi Hayase
Physica Status Solidi (A), 210, 1846-1850, 01 May 2013, Peer-reviwed
Scientific journal, English

Effect of extended pi-conjugation on photovoltaic performance of dye sensitized solar cells based on unsymmetrical squaraine dyes
Shyam S. Pandey; Rie Watanabe; Naotaka Fujikawa; Gururaj M. Shivashimpi; Yuhei Ogomi; Yoshihiro Yamaguchi; Shuzi Hayase
TETRAHEDRON, 69, 12, 2633-2639, Mar. 2013, Peer-reviwed
Scientific journal, English

Dye Sensitized Solar Cells Consisting of Metallophthalocyanine Axially Anchored on Metal Oxide Nanoparticles through Metal-O-Metal Linkages-Difference in Photovoltaic Performances between TiO2 and SnO2 Electrode
Byung-wook Park; Qing Shen; Yuhei Ogomi; Shyam S. Pandey; Taro Toyoda; Shuzi Hayase
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY, 2, 1, Q6-Q11, 2013, Peer-reviwed
Scientific journal, English

Solution processable thin film organic photovoltaic cells based on far red sensitive soluble squaraine dyes
Shyam S. Pandey; Takafumi Mizuno; Sandeep Kumar Das; Yuhei Ogomi; Shuzi Hayase
THIN SOLID FILMS, 522, 401-406, Nov. 2012, Peer-reviwed
Scientific journal, English

Electrophoretic deposition onto an insulator for thin film preparation toward electronic device fabrication
Shougo Miyajima; Shuichi Nagamatsu; Shyam S. Pandey; Shuzi Hayase; Keiichi Kaneto; Wataru Takashima
APPLIED PHYSICS LETTERS, 101, 19, Nov. 2012, Peer-reviwed
Scientific journal, English

Relating the Photodynamics of Squaraine-Based Dye-Sensitized Solar Cells to the Molecular Structure of the Sensitizers and to the Presence of Additives
G. de Miguel; M. Marchena; B. Cohen; S. S. Pandey; S. Hayase; A. Douhal
JOURNAL OF PHYSICAL CHEMISTRY C, 116, 42, 22157-22168, Oct. 2012, Peer-reviwed
Scientific journal, English

Dye Sensitized Solar Cells Based on Novel Far Red Sensitizing Unsymmetrical Squaraine Dye Containing Pyrroloquinoline Moiety
Shyam S. Pandey; Naotaka Fujikawa; Rie Watanabe; Yuhei Ogomi; Yoshihiro Yamaguchi; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 51, 10, Oct. 2012, Peer-reviwed
Scientific journal, English

Differences in Dye-Sensitized Photovoltaic Behaviors between SnO2 and TiO2 Electrodes
Kengo Sadamasu; Yuhei Ogomi; Shyam S. Pandey; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 51, 10, Oct. 2012, Peer-reviwed
Scientific journal, English

Novel unsymmetrical squaraine dye bearing cyanoacrylic acid anchoring group and its photosensitization behavior
Gururaj M. Shivashimpi; Shyam S. Pandey; Rie Watanabe; Naotaka Fujikawa; Yuhei Ogomi; Yoshihiro Yamaguchi; Shuzi Hayase
TETRAHEDRON LETTERS, 53, 40, 5437-5440, Oct. 2012, Peer-reviwed
Scientific journal, English

Femto- to Millisecond Photophysical Characterization of Indole-Based Squaraines Adsorbed on TiO2 Nanoparticle Thin Films
G. de Miguel; M. Marchena; M. Ziolek; S. S. Pandey; S. Hayase; A. Douhal
JOURNAL OF PHYSICAL CHEMISTRY C, 116, 22, 12137-12148, Jun. 2012, Peer-reviwed
Scientific journal, English

Photophysics of H- and J-Aggregates of Indole-Based Squaraines in Solid State
G. de Miguel; M. Ziolek; M. Zitnan; J. A. Organero; S. S. Pandey; S. Hayase; A. Douhal
JOURNAL OF PHYSICAL CHEMISTRY C, 116, 17, 9379-9389, May 2012, Peer-reviwed
Scientific journal, English

Research Trend Aiming at High Efficiency Organic Solar Cells
HAYASE Shuzi
The Journal of Japan Institute for Interconnecting and Packaging Electronic Circuits, The Japan Institute of Electronics Packaging, 15, 3, 175-179, 01 May 2012
Japanese

Femto to millisecond observations of indole-based squaraine molecules photodynamics in solution
G. de Miguel; M. Marchena; M. Zitnan; S. S. Pandey; S. Hayase; A. Douhal
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 14, 5, 1796-1805, 2012, Peer-reviwed
Scientific journal, English

Multiple electron injection dynamics in linearly-linked two dye co-sensitized nanocrystalline metal oxide electrodes for dye-sensitized solar cells
Qing Shen; Yuhei Ogomi; Byung-wook Park; Takafumi Inoue; Shyam S. Pandey; Akari Miyamoto; Shinsuke Fujita; Kenji Katayama; Taro Toyoda; Shuzi Hayase
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 14, 13, 4605-4613, 2012, Peer-reviwed
Scientific journal, English

Dye adsorption feature on titania surface and role of dye aggregation inhibitor monitored by quartz crystal microbalance (QCM)
Ryohei Hirota; Yuehi Ogomi; Shyam S. Pandey; Shuzi Hayase
ORGANIC PHOTOVOLTAICS XIII, 8477, 2012, Peer-reviwed
International conference proceedings, English

Flexible transparent conductive oxide-less flat and cylinder dye-sensitized solar cells
Jun Usagawa; Takeshi Kogo; Kengo Sadamasu; Shyam S. Pandey; Yuhei Ogomi; Shuzi Hayase
JOURNAL OF PHOTONICS FOR ENERGY, 2, 2012, Peer-reviwed
Scientific journal, English

Aiming at High Efficiency Dye-Sensitized Solar Cells - From the View Point of Photoconversion Interface
Shuzi Hayase; Yuhei Ogomi; Shyam S. Pandey
ELECTROCHEMISTRY, 79, 10, 761-767, Oct. 2011, Peer-reviwed
Scientific journal, English

Investigating the Role of Dye Dipole on Open Circuit Voltage in Solid-State Dye-Sensitized Solar Cells
Shyam S. Pandey; Kyung-Young Lee; Azwar Hayat; Yuhei Ogomi; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 50, 6, Jun. 2011, Peer-reviwed
Scientific journal, English

Fabrication of Electron Passes in Nano-TiO2 Layer by High-Velocity Oxy-Fuel Method for Dye-Sensitized Solar Cells
Terumi Nishimura; Daishiro Nomura; Shohhei Sakaguchi; Hideaki Nagayoshi; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 50, 2, Feb. 2011, Peer-reviwed
Scientific journal, English

Hybrid Dye-Sensitized Solar Cells Consisting of Double Titania Layers for Harvesting Light with Wide Range of Wavelengths
Kengo Sadamasu; Takafumi Inoue; Yuhei Ogomi; Shyam S. Pandey; Shuzi Hayase
APPLIED PHYSICS EXPRESS, 4, 2, Feb. 2011, Peer-reviwed
Scientific journal, English

One-Dimensional Nanostructure Arrays for Dye-Sensitized Solar Cells
Patcharee Charoensirithavorn; Takashi Sagawa; Shuzi Hayase; Susumu Yoshikawa
JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME, 133, 1, Feb. 2011, Peer-reviwed
Scientific journal, English

Multiple electron injection from dyes to titania layer for high efficiency-dye-sensitized solar cells
Byung-Wook Park; Kengo Sadamasu; Yuhei Ogomi; Akari Miyamoto; Shinsuke Fujita; Shyam S. Pandey; Qing Shen; Taro Toyoda; Shuzi Hayase
Conference Record of the IEEE Photovoltaic Specialists Conference, 001187-001191, 2011
International conference proceedings, English

Bis(alkyl-thiophene) thienothiophene as hole-transport organic semiconductor
Kazuhiro Takamiya; Shuhei Ishikawa; Daisuke Adachi; Shinya Oku; Shuichi Nagamatsu; Wataru Takashima; Shuzi Hayase; Keiichi Kaneto
9TH INTERNATIONAL CONFERENCE ON NANO-MOLECULAR ELECTRONICS, 14, 2011, Peer-reviwed
International conference proceedings, English

Transparent conductive oxideless tandem dye-sensitized solar cells consisting of light-splitting structures
Jun Usagawa; Masaki Kaya; Yuhei Ogomi; Shyam S. Pandey; Shuzi Hayase
JOURNAL OF PHOTONICS FOR ENERGY, 1, 2011, Peer-reviwed
Scientific journal, English

Fine tuning the structure of unsymmetrical squaraine dyes towards the development of efficient dye-sensitized solar cells
Shyam S. Pandey; Rie Watanabe; Naotaka Fujikawa; Yuhei Ogomi; Yoshihiro Yamaguchi; Shuzi Hayase
NEXT GENERATION (NANO) PHOTONIC AND CELL TECHNOLOGIES FOR SOLAR ENERGY CONVERSION II, 8111, 2011, Peer-reviwed
International conference proceedings, English

Relationship Between I-3(-) Diffusion in Titania Nanopores Modified with Dyes and Open Circuit Voltage of Dye-Sensitized Solar Cell
Azwar Hayat; Shyam S. Pandey; Yuhei Ogomi; Shuzi Hayase
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 158, 7, B770-B771, 2011, Peer-reviwed
Scientific journal, English

Electron Injection from Linearly Linked Two Dye Molecules to Metal Oxide Nanoparticles for Dye-Sensitized Solar Cells Covering Wavelength Range from 400 to 950 nm
Byung-wook Park; Takafumi Inoue; Yuhei Ogomi; Akari Miyamoto; Shinsuke Fujita; Shyam S. Pandey; Shuzi Hayase
APPLIED PHYSICS EXPRESS, 4, 1, Jan. 2011, Peer-reviwed
Scientific journal, English

Tandem dye-sensitized solar cells consisting of floating electrode in one cell
Kenshiro Uzaki; Shyam S. Pandey; Shuzi Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 216, 2-3, 104-109, Dec. 2010, Peer-reviwed
Scientific journal, English

Probing mechanism of dye double layer formation from dye-cocktail solution for dye-sensitized solar cells
Yuhei Ogomi; Shyam S. Pandey; Shunta Kimura; Shuzi Hayase
THIN SOLID FILMS, 519, 3, 1087-1092, Nov. 2010, Peer-reviwed
Scientific journal, English

Alkyl and fluoro-alkyl substituted squaraine dyes: A prospective approach towards development of novel NIR sensitizers
Shyam S. Pandey; Takafumi Inoue; Naotaka Fujikawa; Yoshihiro Yamaguchi; Shuzi Hayase
THIN SOLID FILMS, 519, 3, 1066-1071, Nov. 2010, Peer-reviwed
Scientific journal, English

Tandem Dye-Sensitized Solar Cells Consisting of Nanoporous Titania Sheet
Kenshiro Uzaki; Shyam S. Pandey; Yuhei Ogimi; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 49, 8, Aug. 2010, Peer-reviwed
Scientific journal, English

Substituent effect in direct ring functionalized squaraine dyes on near infra-red sensitization of nanocrystalline TiO2 for molecular photovoltaics
Shyam S. Pandey; Takafumi Inoue; Naotaka Fujikawa; Yoshihiro Yamaguchi; Shuji Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 214, 2-3, 269-275, Aug. 2010, Peer-reviwed
Scientific journal, English

Synthesis and characterization of squaric acid based NIR dyes for their application towards dye-sensitized solar cells
Takafumi Inoue; Shyam S. Pandey; Naotaka Fujikawa; Yoshihiro Yamaguchi; Shuji Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 213, 1, 23-29, Jun. 2010, Peer-reviwed
Scientific journal, English

Dye-Sensitized Solar Cells Consisting of 3D-Electrodes-A Review: Aiming at High Efficiency From the View Point of Light Harvesting and Charge Collection
Kenshiro Uzaki; Terumi Nishimura; Jun Usagawa; Shuzi Hayase; Mitsuru Kono; Yoshihiro Yamaguchi
JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME, 132, 2, May 2010, Peer-reviwed
Scientific journal, English

Influence of nature of surface dipoles on observed photovoltage in dye-sensitized solar cells as probed by surface potential measurement
Shyam S. Pandey; Shohei Sakaguchi; Yoshihiro Yamaguchi; Shuji Hayase
ORGANIC ELECTRONICS, 11, 3, 419-426, Mar. 2010, Peer-reviwed
Scientific journal, English

TCO-less 3D-DYE-sensitized solar cells consisting of charge separation sheet and direction to high efficiency cells by using TCO-less structure
Jun Usagawa; Kenshiro Uzaki; Sham S. Pandey; Yuhei Ogomi; Yoshihiro Yamaguchi; Mitsuru Kono; Shuzi Hayase
Conference Record of the IEEE Photovoltaic Specialists Conference, 518-522, 2010
International conference proceedings, English

TCO-less 3D dye-sensitized solar cells consisting of charge separation sheet -tandem, hybrid, cylinder and fiber cells-
Jun Usagawa; Kenshiro Uzaki; Masaki Kaya; Takeshi Kougo; Sham S. Pandey; Yuhei Ogomi; Yoshihiro Yamaguchi; Mitsuru Kono; Shuzi Hayase
2010 10th IEEE Conference on Nanotechnology, NANO 2010, 171-175, 2010, Peer-reviwed
International conference proceedings, English

Improvement of Dye-Sensitized Solar Cell Through TiCl4-Treated TiO2 Nanotube Arrays
Patcharee Charoensirithavorn; Yuhei Ogomi; Takashi Sagawa; Shuzi Hayase; Susumu Yoshikawaa
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 157, 3, B354-B356, 2010, Peer-reviwed
Scientific journal, English

Ambipolar Transport in Bilayer Organic Field-Effect Transistor Based on Poly(3-hexylthiophene) and Fullerene Derivatives
Takeomi Morita; Vipul Singh; Shinya Oku; Shuichi Nagamatsu; Wataru Takashima; Shuzi Hayase; Keiichi Kaneto
JAPANESE JOURNAL OF APPLIED PHYSICS, 49, 4, 2010, Peer-reviwed
Scientific journal, English

A Steady Operation of n-Type Organic Thin-Film Transistors with Cyano-Substituted Distyrylbenzene Derivative
Shuichi Nagamatsu; Tetsuji Moriguchi; Toshiya Nagase; Shinya Oku; Kouji Kuramoto; Wataru Takashima; Tatsuo Okauchi; Katsuhiro Mizoguchi; Shuji Hayase; Keiichi Kaneto
APPLIED PHYSICS EXPRESS, 2, 10, 101502, Oct. 2009, Peer-reviwed
Scientific journal, English

Dye-Sensitized Solar Cells : Present and Future
HAYASE Shuzi
Journal of The Adhesion Society of Japan, The Adhesion Society of Japan, 45, 8, 313-320, 01 Aug. 2009
Japanese

Electrochemiluminescence Devices Consisting of ZnO Nanorods Vertically Grown on Substrate
Tomohito Tanaka; Hiroshi Takishita; Takashi Sagawa; Susumu Yoshikawa; Shuzi Hayase
CHEMISTRY LETTERS, 38, 7, 742-743, Jul. 2009, Peer-reviwed
Scientific journal, English

Transparent conductive oxide layer-less three dimensional dye sensitized solar cells: Fabrication of ionic path in three dimensional Ti electrode
Takayuki Beppu; Yohei Kashiwa; Shuzi Hayase; Mitsuru Kono; Yoshihiro Yamaguchi
Japanese Journal of Applied Physics, 48, 6, Jun. 2009
Scientific journal, English

Tandem Dye-Sensitized Solar Cells Fabricated on Glass Rod without Transparent Conductive Layers
Jun Usagawa; Shyam S. Pandey; Shuzi Hayase; Mitsuru Kono; Yoshihiro Yamaguchi
APPLIED PHYSICS EXPRESS, 2, 6, Jun. 2009, Peer-reviwed
Scientific journal, English

Transparent conductive oxide layer-less dye-sensitized solar cells consisting of floating electrode with gradient TiOx blocking layer
Yoshikazu Yoshida; Shyam S. Pandey; Kenshiro Uzaki; Shuzi Hayase; Mitsuru Kono; Yoshihiro Yamaguchi
APPLIED PHYSICS LETTERS, 94, 9, Mar. 2009, Peer-reviwed
Scientific journal, English

Preparation of Double Dye-Layer Structure of Dye-Sensitized Solar Cells from Cocktail Solutions for Harvesting Light in Wide Range of Wavelengths
Yusuke Noma; Keita Iizuka; Yuhei Ogomi; Shyam S. Pandey; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 48, 2, Feb. 2009, Peer-reviwed
Scientific journal, English

Research Trends of Dye-Sensitized Solar Cells
Hayase Shuzi
Annals of the High Performance Paper Society, Japan, High Performance Paper Society, Japan, 48, 47-51, 2009, Dye-sensitized solar cell is expected as one of the next generation solar cells. Energy-conversion efficiency record reaches 10.4%, which is almost the same as that of amorphous silicone solar cells commercially available. This article summarizes the recent research trends of the solar cells from the viewpoint of high efficiency, low cost, solidification systems and module structures. Tandem cells with a floating electrode are described as one of our recent achievements. The demands for films and papers are also summarized.
Japanese

A facile route to TiO2 nanotube arrays for dye-sensitized solar cells
Patcharee Charoensirithavorn; Yuhei Ogomi; Takashi Sagawa; Shuzi Hayase; Susumu Yoshikawa
JOURNAL OF CRYSTAL GROWTH, 311, 3, 757-759, Jan. 2009, Peer-reviwed
Scientific journal, English

Effect of Heat-Treatment on Electron Transport Process in TiO2 Nanotube Arrays Prepared Through Liquid Phase Deposition for Dye-Sensitized Solar Cells
Patcharee Charoensirithavorn; Yuhei Ogomi; Takashi Sagawa; Shuzi Hayase; Susumu Yoshikawa
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 156, 11, H803-H807, 2009, Peer-reviwed
Scientific journal, English

Probing TiO2/Dye Interface in Dye Sensitized Solar Cells Using Surface Potential Measurement
Shohei Sakaguchi; Shyam S. Pandey; Keisuke Okada; Yoshihiro Yamaguchi; Shuji Hayase
APPLIED PHYSICS EXPRESS, 1, 10, Oct. 2008, Peer-reviwed
Scientific journal, English

Direction to High Efficiency-dye-sensitized Solar Cells
HAYASE Shuzi
IEEJ Transactions on Fundamentals and Materials, The Institute of Electrical Engineers of Japan, 128, 9, 573-576, 01 Sep. 2008, The efficiency of dye-sensitized solar cells reached 11% which exceeded that of amorphous Si solar cells. The next target is 15 % efficiency. Focus is put on light harvesting and electron collecting performances to increase the efficiency. Tandem and hybrid cells have been reported to harvest light with wide range of wavelength. Electron collecting performances are improved by surface passivation of nano-titania particles. The research trends including our results are reported.
Japanese

I-2-Resistant TiOx/Ag Collector Fabricated by Arc Plasma Deposition for Dye-Sensitized Solar Cells
Yorikazu Yoshida; Yusuke Noma; Yohei Kashiwa; Shinichi Kojima; Takehito Katoh; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 47, 8, 6484-6487, Aug. 2008, Peer-reviwed
Scientific journal, English

Tio2 surface state control for dye sensitized solar cells with high efficiency and the solidification-fabrication of charge carrier path
Fumi Inakazu; Yuhei Ogomi; Yusuke Noma; Yoshihisa Fujita; Mitsuru Kono; Yoshihiro Yamaguchi; Yohie Kashiwa; Takeshi Kogo; Shuzi Hayase
Materials Research Society Symposium Proceedings, 1031, 43-48, 2008
International conference proceedings, English

Quasi-solid dye sensitized solar cells having straight ion paths: Proposal of high-efficiency QDSCs consisting of two carrier density layers
Takeshi Kogo; Shuzi Hayase; Tatsuo Kaiho; Mitsuru Taguchi
Journal of the Electrochemical Society, 155, 9, K166-K169, 2008, Peer-reviwed
Scientific journal, English

Surface state passivation effect for nanoporous TiO2 electrode evaluated by thermally stimulated current and application to all-solid state dye-sensitized solar cells
Yuusuke Noma; Takashi Kado; Daisuke Ogata; Yoshitaka Hara; Shuzi Hayase
JAPANESE JOURNAL OF APPLIED PHYSICS, 47, 1, 505-508, Jan. 2008, Peer-reviwed
Scientific journal, English

Influence of alkyl dihalide gelators on solidification of dye-sensitized solar cells
Shinji Murai; Satoshi Mikoshiba; Shuzi Hayase
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 91, 18, 1707-1712, Nov. 2007, Peer-reviwed
Scientific journal, English

Quasi-solid dye sensitized solar cell with straight ion paths - Proposal of hybrid electrolytes for ionic liquid-type electrolytes
Takehito Kato; Shuzi Hayase
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 154, 1, B117-B121, 2007, Peer-reviwed
Scientific journal, English

Dye-sensitized solar cells with high efficiency - From interface control to solidification - art. no. 665606
Yuhei Ogomi; Shohei Sakaguchi; Shuzi Hayase
ORGANIC PHOTOVOLTAICS VIII, 6656, 65606-65606, 2007, Peer-reviwed
International conference proceedings, English

Differences in characteristics of dye-sensitized solar cells containing acetonitrile and ionic liquid-based electrolytes studied using a novel model
Toshihiro Oda; Shigenori Tanaka; Shuzi Hayase
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 90, 16, 2696-2709, Oct. 2006, Peer-reviwed
Scientific journal, English

Dye-sensitized Solar Cells Consisting of CuI-containing Gels
KADO Takashi; SOEDA Kuniko; NEGORO Kenji; HAYASE Shuzi
Chemistry Letters, The Chemical Society of Japan, 35, 4, 444-445, 05 Apr. 2006, CuI-containing gels for dye-sensitized solar cells are reported. CuI-containing gels consist of CuI, methylpropylimidazolium iodide, iodine, and gelators consisting of polyvinylpyridine and tetra(iodomethyl)benzene. The efficiency increases with an increase in the amount of iodine molecules in the presence of methylpropylimidazolium iodide, which is different from the previous reports in the absence of methylpropylimidazolium iodide. Solidification of the sticky CuI layers is carried out by cross-linking reaction of gelators without decreasing the photovoltaic performances.
English

Latent gel electrolyte precursors for quasi-solid dye sensitized solar cells - The comparison of nano-particle cross-linkers with polymer cross-linkers
T Kato; A Okazaki; S Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 179, 1-2, 42-48, Apr. 2006, Peer-reviwed
Scientific journal, English

Analysis of dominant factors for increasing the efficiencies of dye-sensitized solar cells: Comparison between acetonitrile and ionic liquid based electrolytes
Toshihiro Oda; Shigenori Tanaka; Shuzi Hayase
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, 45, 4 A, 2780-2787, Apr. 2006
Scientific journal

Fabrication of ion-paths for ionic liquid type quasi-solid dye sensitized solar cell
Takashi Kado; Takehito Kato; Takeshi Kogo; Fumi Inakazu; Yusuke Noma; Yuhei Ogomi; Yoshihiro Yamaguchi; Mitsuru Kohno; Shuzi Hayase
Materials Research Society Symposium Proceedings, Materials Research Society, 965, 392-397, 2006
International conference proceedings, English

Quasi-solid dye sensitized solar cells equipped with hybrid electrolytes consisting of linear conduction paths
Shuzi Hayase; Takehito Kato; Fumi Inakazu; Keisuke Okada
Polymer Preprints, Japan, 55, 2, 4647-4648, 2006
International conference proceedings, Japanese

Quasi-solid dye sensitized solar cells bearing straight ion-paths
Shuzi Hayase; Takehito Kato; Shuhei Tanaka
Polymer Preprints, Japan, 55, 2, 4144-4145, 2006
International conference proceedings, Japanese

Ru dye uptake under pressurized CO 2 improvement of photovoltaic performances for dye-sensitized solar cells
Yuhei Ogomi; Shohei Sakaguchi; Takashi Kado; Mitsuru Kono; Yoshihiro Yamaguchi; Shuzi Hayase
Journal of the Electrochemical Society, 153, 12, A2294-A2297, 2006
Scientific journal, English

Quasi-solid dye sensitized solar cells with ionic liquid type gel electrolytes
T. Kato; A. Okazaki; Y. Ogomi; T. Kado; S. Tanaka; T. Beppu; S. Hayase
ECS Transactions, 1, 32, 23-30, 2006
International conference proceedings

Quasi-solid dye-sensitized solar cells containing nanoparticles modified with ionic liquid-type molecules
T Kato; T Kado; S Tanaka; A Okazaki; S Hayase
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 153, 3, A626-A630, 2006, Peer-reviwed
Scientific journal, English

Dye sensitized solar cells consisting of ionic liquid and solidification
Yuhei Ogomi; Takehito Kato; Shuzi Hayase
JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY, 19, 3, 403-408, 2006, Peer-reviwed
Scientific journal, English

Dye Sensitized Solar Cells : The Research Trend and the Future
HAYASE Shuzi
Kobunshi, The Society of Polymer Science, Japan, 54, 12, 878-881, 01 Dec. 2005, 色素増感太陽電池の研究開発動向をまとめた。要素研究では性能向上と固体化に関する研究に焦点。プラスチック化で軽量化,タンデム型で性能向上を狙う。大型モジュールの試作で耐久性を含めた総合試験が始まった。今後,実用に近い環境での試験が加速する。
Japanese

Low-temperature Fabrication of Nano-porous TiO_2 Layers for Dye-sensitized Solar Cells. Fabrication of Ion-diffusion Paths
KADO Takashi; KUBOTA Yukihumi; HAYASE Shuzi
Chemistry Letters, The Chemical Society of Japan, 34, 7, 1006-1007, 05 Jul. 2005, In dye-sensitized solar cells, it is required to build up both of ion paths and electron paths in TiO₂ layers for low-temperature fabrication process. In this report, ion paths are focused on. Semiconductive layers are composed of TiO₂ nanocrystals (P25) and needle-shape TiO₂ crystals (FTL 100). By adding 20% of the needles into P25, photocurrent increased from 5.3 to 7.7 mA/cm². Pore distributions, surface areas, Cole–Cole plot and currents passing through TiO₂ layers were measured. These results suggest that the increase in the photocurrent is associated with the formation of ion paths in TiO₂ layers.
English

Photooxidized Polysilane Binders for Low Temperature Fabrication of Dye-sensitized Solar Cells
SOEDA Kuniko; KOSUGI Daishi; KADO Takashi; HAYASE Shuzi
Chemistry Letters, The Chemical Society of Japan, 34, 5, 650-651, 05 May 2005, Photooxidized polysilanes were evaluated as binders connecting nano-TiO₂ particles for low temperature baking process. Both of Jsc and Voc increased after TiO₂ nanoparticles (P25) were connected with photooxidized polysilanes. The amount of dyes adsorbed on TiO₂ layers, TiO₂ flat band potentials, electron diffusion co-efficient, electron life time were measured. The increases in the Jsc and Voc were associated with increases in electron diffusion coefficients and electron life time in TiO₂ layers.
English

Latent gel electrolyte precursors for quasi-solid dye sensitized solar cells
Takehito Kato; Akio Okazaki; Shuzi Hayase
Chemical Communications, Royal Society of Chemistry, 3, 363-365, 21 Jan. 2005
Scientific journal, English

Quasi-solid-state dye sensitized solar cells by use of nano-particles chemically bonded with ionic liquid type molecules
Takehito Kato; Akio Okazaki; Takasi Kado; Wataru Takashima; Keichi Kaneto; Shuzi Hayase
Polymer Preprints, Japan, 54, 1, 1444, 2005
International conference proceedings, Japanese

Quasi-solid-state dye sensitized solar cells by use of nano materials modified with imidazolium salts bearing long alkyl groups
Shuzi Hayase; Takehito Kato; Akio Okazaki; Shuhei Tanaka; Takayuki Beppu; Takashi Kado
Polymer Preprints, Japan, 54, 2, 4627-4628, 2005
International conference proceedings, Japanese

Quasi-solid-state dye sensitized solar cells by use of ionic liquid type latent gel electrolyte precursors
Takehito Kato; Akio Okazaki; Yuhei Ogomi; Wataru Takashima; Keichi Kaneto; Shuzi Hayase; Koichi Yamashita
Polymer Preprints, Japan, 54, 1, 1445, 2005
International conference proceedings, Japanese

Fabrication of quasi-solidified dye sensitized solar cells - Relationship between crosslinker structure and PV performance
Shuzi Hayase; Takehito Kato; Akio Okazaki; Shuhei Tanaka; Takashi Kado
Polymer Preprints, Japan, 54, 2, 4591-4592, 2005
International conference proceedings, Japanese

Increase in electrochemiluminescence intensities by use of nanoporous TiO2 electrodes
S Okamoto; K Soeda; T Iyoda; T Kato; T Kado; S Hayase
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 152, 8, A1677-A1681, 2005, Peer-reviwed
Scientific journal, English

Additives for increased photoenergy conversion efficiencies of quasi-solid, dye-sensitized solar cells
T Kato; M Fujimoto; T Kado; S Sakaguchi; D Kosugi; R Shiratuchi; W Takashima; K Kaneto; S Hayase
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 152, 6, A1105-A1108, 2005, Peer-reviwed
Scientific journal, English

Quasi-solid dye sensitized solar cells solidified with chemically cross-linked gelators - Control of TiO2/gel electrolytes and counter Pt/gel electrolytes interfaces
S Sakaguchi; H Ueki; T Kato; T Kado; R Shiratuchi; W Takashima; K Kaneto; S Hayase
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 164, 1-3, 117-122, Jun. 2004, Peer-reviwed
Scientific journal, English

Quasi-solid-dye-sensitized solar cells control of TiO2-gel electrolyte interfaces
S Hayase; T Kato; T Kado; S Sakaguchi; H Ueki; W Takashima; K Kaneto; R Shiratuchi; H Sumino; S Murai; S Mikoshiba
ORGANIC PHOTOVOLTAICS IV, 5215, 16-23, 2004, Peer-reviwed
International conference proceedings, English

Quasi-solid dye sensitised solar cells filled with ionic liquid - increase in efficiencies by specific interaction between conductive polymers and gelators
Y Shibata; T Kato; T Kado; R Shiratuchi; W Takashima; K Kaneto; S Hayase
CHEMICAL COMMUNICATIONS, 21, 21, 2730-2731, Nov. 2003, Peer-reviwed
Scientific journal, English

Composite Catalysts Consisting of Aluminum Complexes and Silanol Derivatives for Addition Reaction of Epoxy Resins with Active Hydrogen Compounds.
SUZUKI Shuichi; HAYASE Shuzi
Kobunshi Kagaku, The Society of Polymer Science, Japan, 51, 5, 315-321, 1994, The composite catalysts (AS catalysts) consisting of aluminum complexes and silanol derivatives have been found to acceralate the addition reactions of epoxy resins and active hydrogen compounds. Catalytic activity was not observed when one of the two components is absent, as in the case of the ring opening polymerization of epoxy resins. The catalytic activity was affected by the structures of aluminum complexes and silanol derivatives. Triphenyl silanol was more active than diphenyldiethoxysilane which was decomposed thermally to form a silanol. The acceleration effects were observed even with a small amount of the catalyst, i. e., 0.1wt% of catalyst. The DSC curve of the product from an epoxy resin and an aromatic amine with the AS catalyst showed an exothermic peak 30°C lower than that of the non-catalyst resin systems. The epoxy resins cured with the AS catalysts exhibit excellent electrical, mechanical, physical, and thermal properties which meet the requirements of electrical and space/aeronautical applications.
Japanese

色素増感太陽電池からハロゲン化ペロブスカイト太陽電池へ : 最近の研究動向と今後の展望—Transition from Dye Sensitized Solar Cells to Halide Perovskite Solar Cells : Recent Progress and Future Perspective—特集 第17回光機能性材料セミナー
早瀬 修二
Feb. 2022, 日本写真学会誌 = Journal of the Society of Photography and Imaging of Japan, 85, 1, 45-52, Japanese, 0369-5662, AN00191766

Tin lead perovskite solar cells with narrow band gap working as bottom cell of tandem solar cell
Hayase Shuzi
The Japan Photovoltaic Society, 12 Oct. 2021, Proceedings of the Annual Meeting of the Japan Photovoltaic Society, 1, 12-13, Japanese, 2436-6498

スズ系ペロブスカイト太陽電池の高電圧、高効率化
早瀬 修二
光機能材料研究会, Aug. 2021, 会報光触媒 = Photocatalysis, 66, 4-9, Japanese, 1345-5818, 40022679070

Research trend of Pb free perovskite solar cells
早瀬 修二
電気学会, 01 Mar. 2021, 電気学会研究会資料. DEI, 2021, 33, 1-3, Japanese, 40022544133

ペロブスカイト/シリコンタンデム太陽電池の開発—Development of Perovskite/Silicon Tandem Solar Cells—タンデム太陽電池の最近の動向
五反田 武志; 早瀬 修二; 松井 卓矢; 齋 均
2021, 応用電子物性分科会誌 = Bulletin of solid state physics and applications / 応用物理学会応用電子物性分科会 編, 27, 2, 51-56, Japanese, 1341-5123

Quantum dot size dependence of the photoexcited carrier dynamics in PbS quantum dot film
小栗直己; 朝倉良太; DING C.; 早瀬修二; 豊田太郎; SHEN Q.
2021, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 68th, 202102240201278386

Optical Properties and Photoexcited Carrier Dynamics and Stability of APbBr₃ Perovskite NCs
矢嶋祥太; 川畑健太郎; LIU Feng; ZHANG Yaohong; DING Chao; 豊田太郎; 早瀬修二; SHEN Qing
2021, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 68th, 202102247523145609

Development of Perovskite/Silicon Tandem Solar Cells
五反田武志; 五反田武志; 西村滉平; CHEN Mengmeng; 廣谷太佑; 廣谷太佑; 早瀬修二; 齋均; 松井卓矢; 箕輪直子; 戸張智博; 齊田穣
2021, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 68th, 202102268787138678

Large-Scale Flexible Perovskite Solar Cells with p-i-n Structure
菊池創太; 早瀬修二
2021, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 68th, 202102285806584166

Synthesis of CsSn_xPb_1-xI₃ Perovskite QDs and Their Optical Properties
矢嶋祥太; DING Chao; 豊田太郎; 早瀬修二; SHEN Qing
2021, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 82nd, 202202231973950590

Improvement of conversion efficiency of Tin perovskite solar cells by Multi-anion substitution
西村滉平; KAMARUDIN Muhammad Akmal; SHEN Qing; 飯久保智; 峯元高志; 吉野賢二; 早瀬修二
2021, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 82nd, 202202232355408872

Modularization of p-i-n structure perovskite solar cells using solvents
菊池創太; 早瀬修二
2021, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 82nd, 202202236521769351

Improvement of conversion efficiency for tin perovskite solar cells using bromide substitution
西村滉平; KAMARUDIN Muhammad Akmal; SHEN Qing; 飯久保智; 峯元高志; 吉野賢二; 早瀬修二
2021, 電気化学秋季大会講演要旨集(CD-ROM), 2021, 202202211209742915

High Efficiency Lead-free Wide Bandgap Perovskite Solar Cells via Guanidinium Bromide Incorporation
カマルディン ムハマドアクマル; 沈 青; 早瀬 修二
2021, ACS Applied Energy Materials, 未定, Peer-reviwed, with international co-author(s)

Dependence of the optical properties and carrier dynamics of CsSn_xPb_1-xBr₃ Perovskite nanocrytal on the ratio of tin to lead
Kawabata Kentaro; Liu Feng; Zhang Yaohong; Shen Qing; Toyoda Taro; Hayase Shuzi
The Japan Society of Applied Physics, 26 Aug. 2020, JSAP Annual Meetings Extended Abstracts, 2020.2, 1937-1937, Japanese, 2436-7613

Research Trend on Pb Free Sn Perovskite Solar Cell
Hayase Shuzi
The Japan Society of Applied Physics, 26 Aug. 2020, JSAP Annual Meetings Extended Abstracts, 2020.2, 167-167, Japanese, 2436-7613

Relationship between Built-in Potential and Open-circuit Voltage in Tin-based Perovskite Solar Cells
Hirotani Daisuke; Kamarudin Akmal; Nishimura Kohei; Qing Shen; Taro Toyoda; Hayase Shuzi
The Japan Society of Applied Physics, 26 Aug. 2020, JSAP Annual Meetings Extended Abstracts, 2020.2, 1650-1650, Japanese, 2436-7613

Effect of A site cations on Sn vacancy in Sn perovskite
Iikubo Satoshi; Okumura Taichi; Okumura Ryo; Hayase Shuzi
The Japan Society of Applied Physics, 26 Aug. 2020, JSAP Annual Meetings Extended Abstracts, 2020.2, 1654-1654, Japanese, 2436-7613

Efficiency improvement of Sn-perovskite solar cells by A-site multicationization
Nishimura Kohei; Akmal Kamarudin Muhammad; Hirotani Daisuke; Hamada Kengo; Iikubo Satoshi; Shen Qing; Minemoto Takashi; Yoshino Kenji; Hayase Shuzi
The Japan Society of Applied Physics, 26 Aug. 2020, JSAP Annual Meetings Extended Abstracts, 2020.2, 1653-1653, Japanese, 2436-7613

Enhancement of Stability and efficiency of perovskite solar battery by using sulfur atom
早瀬 修二
硫酸協会, Aug. 2020, 硫酸と工業, 73, 8, 88-94, Japanese, 0370-8047, 40022335090, AN00251176

Improvement of conversion efficiency of SnGe-perovskite solar cell by ethylammonium substitution
Nishimura Kohei; Muhammad Akmal Kamarudin; Hirotani Daisuke; Hamada Kengo; Iikubo Satoshi; Shen Qing; Minemoto Takashi; Yoshino Kenji; Hayase Shuzi
The Japan Society of Applied Physics, 28 Feb. 2020, JSAP Annual Meetings Extended Abstracts, 2020.1, 2403-2403, Japanese, 2436-7613

Research trend for Pb-free perovskite solar cells
Hayase Shuzi
The Japan Society of Applied Physics, 28 Feb. 2020, JSAP Annual Meetings Extended Abstracts, 2020.1, 218-218, Japanese, 2436-7613

Optical absorption of PbS quantum dots with ligands on single crystal TiO₂ - Comparative study of photoaocoustic and absorbance spectroscopies -
Toyoda Taro; Shen Qing; Nakazawa Naoki; Yoshihara Yasuha; Kamiyama Keita; Hayase Shuzi
The Japan Society of Applied Physics, 28 Feb. 2020, JSAP Annual Meetings Extended Abstracts, 2020.1, 2400-2400, Japanese, 2436-7613

Photoexcited carrier dynamics of PbS/CdS core-shell quantum dots
Oguri Naoki; Ding Chao; Yoshida Koji; Zhang Yaohong; Hayase Shuzi; Toyoda Taro; Shen Qing
The Japan Society of Applied Physics, 28 Feb. 2020, JSAP Annual Meetings Extended Abstracts, 2020.1, 2879-2879, Japanese, 2436-7613

Standardization of Perovskite Films Deposition Process by in-situ Observation
廣谷太佑; 濱田健吾; KAMARUDIN Akmal; QING Shen; 豊田太郎; 早瀬修二
2020, 日本化学会春季年会講演予稿集(CD-ROM), 100th, 202002289223150806

Conversion Efficiency Improvement of SnGe-perovskite Solar Cells by Ethylammonium Substitution
西村滉平; KAMARYDIN Muhamad Akmal; 廣谷太佑; 濱田健吾; SHEN Qing; 飯久保智; 峯元高志; 吉野賢二; 早瀬修二; 早瀬修二
2020, 電気化学会大会講演要旨集(CD-ROM), 87th, 202002229326764906

研究総括の役割（さきがけ）
早瀬 修二
公益社団法人 応用物理学会, 10 Aug. 2019, 応用物理, 88, 8, 543-545, Japanese, 0369-8009, 2188-2290, 130007709597, AN00026679

The Info-powered Energy System that Supports the Social Quality of a Super Smart Society
横川 慎二; 市川 晴久; 曽我部 東馬; 澤田 賢治; 早瀬 修二; 大川 富雄
日本品質管理学会, Jul. 2019, 品質, 49, 3, 228-231, Japanese, 0386-8230, 40021976970, AN00354769

高エネルギー変換効率が期待される太陽電池の作製技術の開発 : 中間バンド型太陽電池の液相プロセス作製
細川 浩司; 澤田 拓也; 小此木 明徳; 佐藤 治之; 矢野 聡宏; 玉置 亮; 岡田 至崇; 尾込 裕平; 早瀬 修二
日本工業出版, May 2019, クリーンエネルギー, 28, 5, 22-28, Japanese, 0918-7510, 40021903309, AN10502148

Perovskite solar cells with narrow bandgap : Approach for Pb-free perovskite solar cells
早瀬 修二
電気学会, 22 Jan. 2019, 電気学会研究会資料. DEI, 2019, 1, 41-43, Japanese, 0913-5685, 40021797599, AN10013334

Micro-scale current path distributions of Zn 1-x Mg x O-coated SnO 2 :F transparent electrodes prepared by sol-gel and sputtering methods in perovskite solar cells
Jakapan Chantana; Teruaki Hirayama; Chao Ding; Yu Kawano; Qing Shen; Kenji Yoshino; Shuzi Hayase; Takashi Minemoto
01 Jan. 2019, Thin Solid Films, 669, 455-460, 0040-6090, 85056826714

異なるTiO₂結晶面に吸着した半導体量子ドットの光吸収とUrbach則-光熱変換法と吸光度法による評価-
豊田太郎; SHEN Qing; 神山慶太; 早瀬修二
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902218315783788

Aサイト置換によるSn-Perovskite太陽電池特性と結晶歪みの相関
西村滉平; 廣谷太佑; KAMARUDIN Muhammad Akmal; 飯久保智; SHEN Qing; 豊田太郎; 峯元高志; 吉野賢二; 早瀬修二
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902238899556452

TiO₂単結晶基板上にPbS量子ドット間距離を制御吸着した系の光音響法と光電子収量法による評価:量子ドット増感系
豊田太郎; SHEN Qing; 中澤直樹; 吉原泰葉; 神山慶太; 早瀬修二
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902256643166828

PbS量子ドット薄膜における光励起キャリアダイナミクス-量子ドットサイズの依存性-
北畠有紀子; 北畠有紀子; 大図修平; DING C.; ZHANG Y.; 豊田太郎; 早瀬修二; 片山建二; SHEN Q.
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902268098357964

液相法で作製したPbS量子ドット/ペロブスカイト中間バンド型太陽電池-(1)設計と作製
細川浩司; 玉置亮; 澤田拓也; 小此木明徳; 佐藤治之; 尾込裕平; 尾込裕平; 早瀬修二; 岡田至崇; 矢野聡宏
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902224694841483

液相法で作製したPbS量子ドット/ペロブスカイト中間バンド型太陽電池-(2)特性評価
玉置亮; 細川浩司; 澤田拓也; 小此木明徳; 佐藤治之; 尾込裕平; 尾込裕平; 早瀬修二; 岡田至崇; 矢野聡宏
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902237900384358

界面パッシベーションによるPbS量子ドット/ZnOナノワイヤヘテロ接合太陽電池の開放電圧の向上
中村眞子; DING C.; 大図修平; 吉田康二; 吉原泰葉; 豊田太郎; 早瀬修二; SHEN Q.
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902237334555263

逆オパール構造TiO₂光電極を用いたSb₂S₃固体型増感太陽電池
吉原泰葉; 豊田太郎; 早瀬修二; SHEN Qing
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902269007839710

CsSn_xPb_1-xBr₃ペロブスカイト量子ドットの合成と光学的特性
川畑健大朗; LIU Feng; 安田寛啓; 吉田康二; 豊田太郎; 早瀬修二; SHEN Qing
2019, 応用物理学会春季学術講演会講演予稿集(CD-ROM), 66th, 201902280478540183

塗布型ハロゲン化ペロブスカイト薄膜の熱伝導率
西尾僚馬; 與那嶺亮; 佐脇卓弥; 廣谷太佑; SAINI Shrikant; 早瀬修二; 矢吹智英; 宮崎康次
2019, 日本伝熱シンポジウム講演論文集(CD-ROM), 56th, 1346-1532, 201902230664269053

様々な状態におけるペロブスカイト太陽電池の発電挙動について
斎藤英純; 青木大輔; 馬飼野信一; 高木克彦; 早瀬修二
2019, 電気化学会大会講演要旨集(CD-ROM), 86th, 201902247570309456

狭バンドギャップを有するペロブスカイト太陽電池の研究開発動向
早瀬修二
2019, 日本化学会春季年会講演予稿集(CD-ROM), 99th, 201902270358512012

PbS量子ドット/ペロブスカイトからなる中間バンド型太陽電池の液相プロセス作製
細川浩司; 玉置亮; 澤田拓也; 小此木明徳; 佐藤治之; 尾込裕平; 早瀬修二; 岡田至崇; 矢野聡宏
2019, 日本化学会春季年会講演予稿集(CD-ROM), 99th, 201902291605017941

塗布型Pb-ペロブスカイトの半導体特性と太陽電池性能評価
廣谷太佑; 前田優太; SUDHIR Pandey Shyam; QING Shen; 豊田太郎; 峯元高志; 吉野賢二; 早瀬修二; 早瀬修二
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902235770180479

相安定性を持つCsSn_xPb_1-xBr₃ペロブスカイト量子ドットの光学的特性
川畑健大朗; LIU Feng; ZHANG Yaohong; DING Chao; 豊田太郎; 早瀬修二; SHEN Qing
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902273298371572

界面パッシベーションによるPbS量子ドット/ZnOナノワイヤーヘテロ接合太陽電池の電荷再結合の抑制
中村眞子; DIMG C.; 豊田太郎; 早瀬修二; SHEN Q.
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902285143814962

Silver Bismuth Halideを用いた鉛フリー太陽電池の研究
濱田健吾; 廣谷太佑; 西村滉平; KAMARUDIN Muhammad Akmal; SHEN Qing; 豊田太郎; MA Tingli; 早瀬修二
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902220327459540

Sn-ペロブスカイト太陽電池の保管による結晶歪みと変換効率の関係
西村滉平; KAMARUDIN Munammad Akmal; 廣谷太佑; 濱田健吾; 飯久保智; SHEN Qing; 豊田太郎; 峯元高志; 吉野賢二; 早瀬修二; 早瀬修二
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902283093521769

FAPbI₃ペロブスカイトナノ結晶の光学特性と半導体基板への光励起電子の移動ダイナミクス
LIN X.; DING C.; ZHANG Y.; LIU F.; CHANTANA Jakapan; 峯元高志; 豊田太郎; 早瀬修二; SHEN Q.
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902232394378132

鉛フリー有機無機ペロブスカイトの電子状態計算
井手敦子; 山本久美子; 奥村崚; 飯久保智; 飯久保智; 早瀬修二; 早瀬修二
2019, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 80th, 201902238764797803

異なるTiO₂結晶面に吸着した半導体量子ドットの光吸収とUrbach則:光熱変換法と吸光度法による評価
豊田太郎; SHEN Qing; 神山慶太; 早瀬修二
2019, 光化学討論会要旨集(CD-ROM), 2019, 201902256188578166

Thermal Conductivity of a Halide Perovskite Thin Film
NISHIO Ryoma; SAINI Shrikant; BARANWAL Ajay Kumar; HAYASE Shuzi; YABUKI Tomohide; MIYAZAKI Koji
In order to improve thermoelectric performance of printed halide perovskite, CsSnI3 thin films were fabricated under different conditions. The cross-plane thermal conductivities of thin films were measured by 3ω method. The surface morphology was observed using Scanning Electron Microscopy. Thin films annealed at 100oC and 130oC had uneven and smaller crystal grains than the one at 70oC. Thin films which have finer crystal grains on the surface tend to have lower thermal conductivity. Influence of phonon grain boundary scattering is considered as one of the factors for lower thermal conductivity. For further development, we will observe cross-sectional crystal grains since the thermal conductivity was measured along the film thickness direction., The Japan Society of Mechanical Engineers, 2019, The Proceedings of the Symposium on Micro-Nano Science and Technology, 2019.10, 21pm1PN304, Japanese, 2432-9495, 130007846953

Thermoelectric Properties of Perovskite Thin Film
Miyazaki Koji; Saini Shirikant; Yabuki Tomohide; Branwal Ajay; Yonamine Akira; Hayase Shuzi
The Japan Society of Mechanical Engineers, 2019, The Proceedings of the Thermal Engineering Conference, 2019, 0108, Japanese, 2424-290X, 130007836119

Review Article, Perovskite solar cells with narrow band gap
Shuzi Hayase
2019, Current Opinion in Electrochemistry, 2018, 11, 146-150., Current Opinion in Electrochem, 146-150, English, Peer-reviwed, Invited, Introduction commerce magazine

シリコンを使わない新しい太陽電池 : 塗布で作製できる高効率ペロブスカイト太陽電池
HAYASE Shuzi
太陽の光を直接電気に変換できる太陽電池は近年急速に普及しているが，ほとんどはシリコン（Si）を原料にしており，作製に1500度以上の高温が必要であった。太陽電池を作るためのエネルギーを回収できる年限（エネルギーペイバックタイム：EPT）は，シリコン系太陽電池は1～2.5年程度とされているが，低温で作製できる塗布型の太陽電池は1年以内といわれている。これまで低温で作製する太陽電池は半導体特性が結晶性シリコンほど良くなく，太陽光変換効率は結晶性シリコンの半分程度であった。最近，低温塗布で作製しても結晶性シリコンに迫る効率を有するペロブスカイト型太陽電池が発明され，世界中で多くの研究者が基礎研究，応用研究，実用化研究に取り組んでいる。本講座では，ペロブスカイト太陽電池の基礎，仕組み，研究動向について解説する。, The Chemical Society of Japan, 20 Jul. 2018, CHEMISTRY & EDUCATION, 66, 7, 346-349, Japanese, 0386-2151, 2424-1830, 130007670978, AN10033386

Facile fabrication of large area oriented conjugated polymer films by ribbon-shaped FTM and its implication on anisotropic charge transport
Atul SM Tripathi; Nikita Kumari; Shuichi Nagamatsu; Shuzi Hayase; Shyam S Pandey
2018, Organic Electronics, 65, 1-7

ルチル型TiO₂単結晶に吸着したPbS量子ドットの結晶成長と電子構造
豊田太郎; SHEN Qing; 堀奏江; 中澤直樹; 神山慶太; 早瀬修二
2018, ナノ学会大会講演予稿集, 16th, 201902218891602106

Thermoelectric Properties of a Coated Perovskite Thin Film
Yonamine Akira; Hirotani Daisuke; Sawaki Takuya; Saini Shrikant; Yabuki Tomohide; Hayase Shuzi; Miyazaki Koji
The discovery of hybrid perovskite can lead to the net-generation energy conversion platforms due to ultra-low thermal conductivity and large Seebeck coefficient. However, optimization of enhanced electrical conductivity is still challenging. In this work, we study growth parameters and thermoelectric properties of a coated CsSnI₃ perovskite thin film. We investigated the effects of mixing time, heating temperature and heating time on the properties of a perovskite film. We measured thermoelectric properties near room temperature and found that growth parameters influence the crystal grain size further the value of figure of merit. Our results shows that the best ZT about 0.086 at room temperature for sample with solvent mixing time about 5 h, heating temperature about 100°C and heating time is 10 min. These result and analysis are preliminary. In future, our plan is to optimize the growth parameters such as spin coating conditions, heating temperature and time to enhance the value of ZT., The Japan Society of Mechanical Engineers, 2018, The Proceedings of the Thermal Engineering Conference, 2018, 0124, Japanese, 2424-290X, 130007637672

Recent progress on Pb free and Sn perovskite solar cells
早瀬 修二
日本太陽エネルギー学会, 2017, 太陽エネルギー = Journal of Japan Solar Energy Society, 43, 2, 29-34, Japanese, 0388-9564, 40021177222, AN00352129

ペロブスカイト太陽電池の現状と将来展望
早瀬 修二
応用物理学会有機分子・バイオエレクトロニクス分科会, Nov. 2016, Molecular electronics and bioelectronics = 応用物理学会,有機分子・バイオエレクトロニクス分科会会誌, 27, 4, 229-242, Japanese, 2423-8805, 40021070507, AN10464559

ペロブスカイト太陽電池における電荷分離・電荷再結合ダイナミックスと光電変換特性との相関
沈 青; 尾込 裕平; 豊田 太郎; 吉野 賢二; 早瀬 修二
応用物理学会有機分子・バイオエレクトロニクス分科会, Nov. 2016, Molecular electronics and bioelectronics = 応用物理学会,有機分子・バイオエレクトロニクス分科会会誌, 27, 4, 263-266, Japanese, 2423-8805, 40021070563, AN10464559

蒸着法によりインターカレートを制御した単純積層型CsPbI₃ペロブスカイト太陽電池の作製
米澤 叶祐; 山本 晃平; SHAHIDUZZAMAN Md; 古本 嘉和; 浜田 啓太郎; RIPOLLES Teresa S.; 桑原 貴之; 高橋 光信; 早瀬 修二; 當摩 哲也
電子情報通信学会, 14 Jul. 2016, 電子情報通信学会技術研究報告 = IEICE technical report : 信学技報, 116, 134, 23-26, Japanese, 0913-5685, 40020907144, AA1123312X

Sn系ペロブスカイト太陽電池と界面制御
尾込 祐平; 早瀬 修二
光機能材料研究会, Jun. 2016, 会報光触媒, 49, 54-61, Japanese, 1345-5818, 40020897143

Pb Free Perovskite Solar Cells : Present and Future
早瀬 修二
大阪工研協会, May 2016, 科学と工業 = Science and industry, 90, 5, 143-149, Japanese, 0368-5918, 40020851295, AN00354430

交互積層法によりインターカレートを制御した蒸着型CsPbI₃ペロブスカイト太陽電池の高効率化
米澤叶祐; 山本晃平; SHAHIDUZZAMAN Md; 古本嘉和; RIPOLLES Teresa S.; 辛川誠; 辛川誠; 桑原貴之; 桑原貴之; 高橋光信; 高橋光信; 早瀬修二; 當摩哲也; 當摩哲也
2016, フロンティア太陽電池セミナー, 1st, 201902279320015925

ヘテロ界面構造がSn系ペロブスカイト太陽電池効率に及ぼす影響
早瀬修二
2016, フロンティア太陽電池セミナー, 1st, 201902299224950307

非Pb系ペロブスカイト型太陽電池の研究開発動向
OGOMI Yuhei; HAYASE Shuji
The Electrochemical Society of Japan, 2016, Electrochemistry, 84, 6, 449-453, English, 1344-3542, 2186-2451, 130005154342, AN00151637

Facile synthesis and characterization of sulfur doped low bandgap bismuth based perovskites by soluble precursor route
Vigneshwaran M; Ohta T; Iikubo S; Kapil G; Ripolles T; Ogomi Y; Ma T; Pandey S; Shen Q; Toyoda T; Yoshino K; Minemoto T; Hayase S
2016, Chemistry of Materials, 28, 18, 6436-6440

Perovskite solar cell covering Infrared regions and trial to Pb-free perovskite solar cells
早瀬 修二
オプトロニクス社, Jul. 2015, オプトロニクス, 34, 7, 82-86, Japanese, 0286-9659, 40020532392, AN00360965

Printable Solar Cells with Self-organized Structure
早瀬 修二
小峰工業出版, Jul. 2015, 化學工業, 66, 7, 553-558, Japanese, 0451-2014, 40020515087, AN00037245

Charge Separation, Recombination and the Mechanism of Improvement in Photovoltaic Properties in Perovskite Solar Cells
沈 青; 尾込 裕平; 豊田 太郎; 吉野 賢二; 早瀬 修二
シーエムシー出版, Jul. 2015, ファインケミカル : 調査・資料・報道・抄録, 44, 7, 26-33, Japanese, 0913-6150, 40021171781, AN00015672

Perovskite Solar Cells : Present and Future
早瀬 修二
シーエムシー出版, Jul. 2015, ファインケミカル : 調査・資料・報道・抄録, 44, 7, 6-13, Japanese, 0913-6150, 40021171702, AN00015672

ペロブスカイト型太陽電池の光活性層界面に生成する光電荷分離状態の時間分解EPR
宮崎晃侑; 長谷川将司; 尾込裕平; 立川貴士; 早瀬修二; 小堀康博
2015, 電子スピンサイエンス学会年会講演要旨集, 54th, 201502215097118287

Coverage up to the infrared region: cocktail perovskite solar cells
HAYASE Shuzi
Printable Pb perovskite solar cells have attracted interest because of a high power conversion efficiency that can reach 17%. However, the light harvesting region has been limited in the visible region to 800 nm. In order to increase the power conversion efficiency further, device structures harvesting energy from the near infrared area are desired. We have succeeded in harvesting light up to 1000 nm by using Sn/Pb cocktail perovskite materials. HOMO-LUMO energy levels were tunable and the stability in air was improved by changing the Sn/Pb ratio. When this was compared to a Pb perovskite solar cell with 14.3% efficiency, the decrease in shunt resistance was remarkable. In order to increase the efficiency further, a design for the charge separation interface that avoids charge recombination is needed., The Japan Society of Applied Physics, 10 Aug. 2014, Oyo Buturi, 83, 8, 660-664, Japanese, 0369-8009, 2188-2290, 130007718603, AN00026679

Non-vacuum Process of CuInS_2 Thin Films From Metal Xanthate Precursors
Mochihara Akiko; Yoshino Kenji; Kawano Minobu; Ogomi Yuhei; Pandey Shyam S.; Shen Qing; Toyoda Taro; Hayase Shuzi
Cu–III–VI_2 compounds have attracted considerable interest because of their possible photovoltaic applications. The ternary semiconductor copper indium sulfide (CuInS_2) is one of the promising materials for thin film solar cells because its bandgap energy of 1.5 eV and the absorption coefficient of 10^5 cm^<-1>. CuInS_2 thin film on glass substrate is grown by dipping-coat from Cu- and In-xanthate solution as precursor materials. X-ray diffraction pattern indicated that peaks of CuInS_2 (112) are observed at 150℃. This temperature is lowest in non-vacuum process of CuInS_2 film. The all CuInS_2 films are p-type conductivity by thermo prove analysis because Cu atom in In site defects are dominant in the samples from EPMA results., Miyazaki University, 31 Jul. 2014, Memoirs of the Faculty of Engineering, Miyazaki University, 43, 81-84, Japanese, 0540-4924, 120007122054, AA00732558

Sn based perovskite solar cells covering infrared region
早瀬 修二
日本太陽エネルギー学会, 2014, 太陽エネルギー = Journal of Japan Solar Energy Society, 40, 4, 17-24, Japanese, 0388-9564, 40020179390, AN00352129

完全封止型円筒型色素増感太陽電池の作製と特徴
早瀬 修二; 馬 廷麗; .藤澤 繁樹
オーム社, Jan. 2014, 101, 1, 54-56, Japanese, 0386-5576, 40019945499, AN10400363

植物由来溶媒による有機半導体薄膜の作製
永松秀一; 高嶋授; PANDEY Shyam S.; 早瀬修二
2013, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 74th, 201302287699045529

Transparent conductive oxide-less dye-sensitized solar cells (TCO-less DSC) with back contact structure
早瀬 修二
日本太陽エネルギー学会, 30 Nov. 2012, 太陽エネルギー = Solar energy, 38, 6, 31-38, Japanese, 0388-9564, 10031128559, AN00352129

One-Step Deposition of Self-Oriented β-Phase Polyfluorene Thin Films for Polarized Polymer Light-Emitting Diodes
DAUENDORFFER Arnaud; MIYAJIMA Shougo; NAGAMATSU Shuichi; TAKASHIMA Wataru; HAYASE Shuzi; KANETO Keiichi
25 Sep. 2012, Applied physics express, 5, 9, "092101-1"-"092101-3", English, 1882-0778, 10031005197, AA12295133

Proposal of high efficiency Quasi-solid dye sensitized solar cell with Amylose-iodine
幸後健; 早瀬修二; 海宝龍夫; 田口充
2012, 鈴鹿工業高等専門学校紀要(Web), 45, 0286-5483, 202002253973241274

豊胸術後の乳がん検診症例の検討
多田豊治; 牧野愛; 早瀬洋子; 高川真唯; 宮本有佳; 浅井葉子; 立松志歩子; 坂本修二; 松本好市
2012, 総合健診, 39, 1, 1347-0086, 201202276233720502

豊胸術後の乳がん検診症例の検討
早瀬洋子; 立松志歩子; 松岡詠巳; 高川真唯; 牧野愛; 浅井葉子; 宮本有佳; 坂本修二; 多田豊治; 松本好市
2011, 人間ドック, 26, 2, 1880-1021, 201102281699311820

Robust Hole Transport in a Thienothiophene Derivative toward Low-cost Electronics
Shinya Oku; Kazuhiro Takamiya; Daisuke Adachi; Shuhei Ishikawa; Shuichi Nagamatsu; Wataru Takashima; Shuzi Hayase; Keiichi Kaneto
Dec. 2010, CHEMISTRY LETTERS, 39, 12, 1315-1316, English, 0366-7022, 1348-0715, 10027468710, WOS:000285814100033

TCO-less dye-sensitized solar cells consisting of all metal electrodes
早瀬 修二
化学工業社, Apr. 2009, 化学工業, 60, 4, 249-255, Japanese, 0451-2014, 40016570609, AN00037245

Solidification of dye sensitized solar cells with self organization
INAKAZU Fumi; KOGO Ken; HAYASE Shuzi
Solidification of dye sensitized solar cells is one of crucial problems to be solved in order to improve the durability. In this report, the solidification of ionic liquid type dye sensitized solar cells is reported. The bottom line is that the solar cell performance is maintained by fabrication of ionic path in the solid media after the solidification. The ionic path is built by use of self organization of ionic liquids. Two layer charge carrier medium consisting of high carrier concentration in the bulk layer and low carrier concentration in the TiO_2 layer is proposed. The former keeps the high conductivity in the solid media and the latter inhibits the back electron transfer from the TiO_2 layer to the electrolyte. The validity of the two layer structure is proved by using several cell structures., The Institute of Electronics, Information and Communication Engineers, 19 Oct. 2007, IEICE technical report, 107, 292, 13-17, Japanese, 0913-5685, 110006452560, AN10013334

Effect of Nanoparticle Addition into Anode Electrodes for Direct Ethanol Fuel Cells
PARK Namsin; SHIRAISHI Takeyuki; KAMISUGI Kazuyoshi; HAYASE Shuzi
05 Jul. 2007, Chemistry letters, 36, 7, 922-923, English, 0366-7022, 10019745720, AA00603318

Dye-sensitized solar cells consisting of ionic liquids
早瀬 修二
電気化学会溶融塩委員会, 2007, Molten salts, 50, 3, 103-108, Japanese, 0916-1589, 40015692503, AN10179993

アミロースヨウ素錯体を用いたイオンパス構築の試み
幸後健; 早瀬修二; 海宝龍夫; 田口充; 細谷佳代
2007, 化学関連支部合同九州大会・外国人研究者交流国際シンポジウム講演予稿集, 44th, 200902241190893668

Dye adsorption, Blocking molecule adsorption and Characteristic of dye sensitized solar cells by Supercritical fluid : Performance improvement of dye sensitized solar cells
SAKAGUCHI Shohhei; HAYASE Syuzi
In order to increase photo voltaic performances, it is necessary to increase the amount dye molecules on TiO2 surfaces and to block the bare TiO2 surfaces with blocking molecules. It has been reported that molecules can diffuse well in super critical liquids. We applied this super critical liquids to dye sensitized solar cells. When adsorptions of dyes and blocking molecules are carried out in super critical CO2 liquids, Jsc and Voc increased, compared with those made in conventional adsorption methods., The Institute of Electronics, Information and Communication Engineers, 01 Sep. 2006, IEICE technical report, 106, 228, 33-36, Japanese, 0913-5685, 110004823598, AN10013334

Fabrication of ion-paths for ionic liquid type quasi-solid dye sensitized solar cell
KATO Takehito; HAYASE Shuzi
Quasi-solid dye sensitized solar cells consisting of porous alumina/ionic liquid electrolyte composites are reported. The straight nano-pores of the porous alumina film are surface-modified with self-organized imidazolium iodide moieties bearing long alkyl groups. By filling the pores with ionic liquids, straight ion paths are fabricated along the aligned the imidazolium moieties, where, iodine molecules are highly concentrated. The swift ion diffusion is explained by Grotthuss mechanism. A new hybrid quasi-solid electrolyte consisting of low I_2 concentration for high light penetration layer and high I_2 concentration for a carrier layer is proposed., The Institute of Electronics, Information and Communication Engineers, 01 Sep. 2006, IEICE technical report, 106, 228, 23-27, Japanese, 0913-5685, 110004823596, AN10013334

Dye Sensitized Solar Cells Consisting of Thermally Stable Nb-doped-Titanium Dioxide Nanowire
BEPPU Takayuki; HAYASE Shuzi
Recently, dye sensitized solar cells using titanium dioxide nanowire and nanotube were reported. Typically, 450℃ anneal process were required for electrode formation. Used by high baking process broke their shapes. In this article, we reported Nb doped titanium dioxide nanowire. The nanowire held shapes and improved photovoltaic performance, The Institute of Electronics, Information and Communication Engineers, 01 Sep. 2006, IEICE technical report, 106, 228, 29-32, Japanese, 0913-5685, 110004823597, AN10013334

ナノ界面制御による擬固体色素増感太陽電池の高性能化
早瀬 修二
Jun. 2006, Molecular electronics and bioelectronics, 17, 2, 121-128, Japanese, 10019161180, AN10464559

Electrodes/Gel Electrolytes interfaces and Quasi-solid Dye Sensitized Solar Cell Efficiencies
HAYASE Shuji
日本太陽エネルギ-学会, 31 Jul. 2003, Journal of Japan Solar Energy Society, 29, 4, 12-17, Japanese, 0388-9564, 10011753731, AN00352129

Yesterday, Today, and Tomorrow of Silicon Chemistry. Application Research of Silicon Compounds to Most Advanced Semiconductor Materials.
早瀬修二
2002, ケイ素化学協会誌, 17, 200902124093627094

色素増感太陽電池の実用化を目指して
早瀬 修二; 角野 裕康; 村井 伸二; 御子 柴智
日本太陽エネルギ-学会, 31 Jul. 2001, 太陽エネルギー = Solar energy, 27, 4, 28-31, Japanese, 0388-9564, 10007498637, AN00352129

Quasi-solid dye sensitized solar cells using gel electrolytes
Hayase Shuzi; Sumino Yasuhiro; Murai Shinji; Mikoshiba Satoshi
We invectigate quasi-solid dye sensitized solar cells(DSC)using chemically crosslinked gels. Ge1-electrolyte-precursors containing room-temperature molten salts and gelators are liquid at first. After they are injected in the cell, gels form in the cell by heating it at 80℃. The gelator was designed to make gels even in the presence of iodine which is an inhibitor for conventional gelators. The gelator is also designed so that gelation occurs by the addition of only 5wt% gelators by controlling the interaction between the gelators and the electrolytes. The quasi-solid DSCs exhibit high performances corresponding to those containing liquid electrolytes., The Institute of Electronics, Information and Communication Engineers, 26 Jul. 2001, Technical report of IEICE. OME, 101, 226, 27-32, Japanese, 0913-5685, 110003301356, AN10013334

Recent progress on narrow band gap perovskite solar cells
Shuzi Hayase
Keynote oral presentation, English, IEEE ICASI, 2019 IEEE International Conference on Applied System Innovation, Invited, IEEE, 北九州市, International conference
12 Apr. 2019

狭バンドギャップペロブスカイト太陽電池の研究開発動向
早瀬修二
Oral presentation, Japanese, 日本化学会, 日本化学会, 甲南大学, Domestic conference
16 Mar. 2019

狭バンドギャップを有するペロブスカイト太陽電池
早瀬修二
Public discourse, Japanese, NICE研究会講演会, NICE研究会, 北九州, Domestic conference
22 Feb. 2019

Recent research progress on narrow band gap perovskite solar cells and Pb free perovskite solar cells
Shuzi Hayase
Keynote oral presentation, English, International Symposium on Solar Energy Materials, Invited, 甲南大学, 甲南大学, International conference
25 Jan. 2019

狭バンドギャップペロブスカイト太陽電池ー鉛を用いないペロブスカイト太陽電池へのアプローチー
早瀬修二
Invited oral presentation, Japanese, 有機エレクトロニクス研究会, Invited, Domestic conference
23 Jan. 2019

Progress of perovskite solar cells with Sn
Shuzi Hayase
Invited oral presentation, English, 12 th Aseanian Conference on Nano-hybrid Solar Cells (NHSC), 12 th Aseanian Conference on Nano-hybrid Solar Cells (NHSC), China, International conference
18 Dec. 2018

Snを含むペロブスカイト太陽電池の現状と今後
早瀬修二
Invited oral presentation, Japanese, 第3回フロンティア太陽電池セミナー, Invited, 宮崎大学, 宮崎, Domestic conference
13 Dec. 2018

SnPb and Pb-Free SnGe Perovskite Solar Cells -Narrow band gap perovskite solar cell
Shuzi Hayase
Invited oral presentation, English, IIJWBME(India-Japan workshop on biomolecular electronics & organic nanotechnologyfor environment preservation-2018), Invited, IIJWBME organizer, India, International conference
06 Dec. 2018

SnPb and Pb-Free SnGe Perovskite Solar Cells -Narrow band gap perovskite solar cell
Shuzi Hayase
Invited oral presentation, English, MRS, MRS, Boston, International conference
29 Nov. 2018

有 機 系 お よ び ペ ロ ブ ス カ イ ト 太 陽 電 池 の 現 状 と 将 来 展 望
早瀬修二
Public discourse, Japanese, 有機エレクトロニクス材料研究会チュートリアル, Invited, 有機エレクトロニクス材料研究会, 九州大学, Domestic conference
20 Nov. 2018

Narrow band gap perovskite solar cell
Shuzi Hayase
Invited oral presentation, English, 7th Korea-Japan Joint Seminar on PV 2018, Invited, 7th Korea-Japan Joint Seminar, Korea, International conference
08 Nov. 2018

ペロブスカイト太陽電池の現状と課題
早瀬修二
Invited oral presentation, Japanese, 半導体パッケージロードマップ講演会, Invited, 半導体パッケージロードマップ員会, 東京, Domestic conference
19 Oct. 2018

Halogenated perovskite solar cells with Sn
Shuzi Hayase
Invited oral presentation, English, IPS22(22nd International Conference on Photochemical Conversion and Storage of Solar Energy), Invited, IPS, China, International conference
31 Jul. 2018

Toward less Pb and Pb-free perovskite solar cells, -Photoelectric conversion in near IR region
Shuzi Hayase
Invited oral presentation, English, The 8th Sungkyun International Solar Forum 2019, Invited, Sungkyunkwan University (SKKU), Seoul, Korea, International conference
26 Jun. 2018

Design guideline to mixed metal SnPb-perovskite solar cells with 17.42% and Pb free Sn-perovskite solar cells with 5.52%
Shuzi Hayase
Invited oral presentation, English, MRS spring meeting, MRS, International conference
04 Apr. 2018

高分子学会

日本化学会

電気化学会

American Chemical Society

Electrochemisal Society

応用物理学会

MRS

小規模創電・蓄電の統合運用を可能にするインターネット型電力プラットフォーム
横川 慎二; 川喜田 佑介; 早瀬 修二; 澤田 賢治; 曽我部 東馬; 中山 舜民; 戸辺 義人
日本学術振興会, 科学研究費助成事業, 電気通信大学, 基盤研究(B), 23H01636
01 Apr. 2023 - 31 Mar. 2027

無鉛型高次元ハライドペロブスカイト材料による太陽電池の高効率・高耐久化
宮坂力
2019 - 2024

Control of the nano-interface of heterojunction quantum dot solar cells and improvement of the charge separation efficiency for multiple excitons
沈 青; 豊田 太郎; 早瀬 修二
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), ホットインジェクション法を用いて、ペロブスカイトAPbX3（X = Cl-、Br-、およびI-）量子ドット（PQD）を作製し、量子ドット太陽電池へ適用した。今年では、PQD のAサイトはそれぞれセシウム（Cs）、メチルアンモニウム（MA ）、またはホルムアミジニウム（FA）とそれらの混晶を用いた。主にAサイトの違いによるPQD結晶構造、光物性と光励起キャリアダイナミクスおよび量子ドット太陽電池の光電変換特性の変化について検討した。透過型電子顕微鏡（TEM）およびエネルギー分散型X線分光（EDS）測定の結果から、混晶したPQDでは、混晶されたＡサイトの成分はPQD全体でランダムに分布していることが判明した。さらに、Ａサイトの混晶化によりPQDのフォトルミネッセンス量子収率が向上したことを見つけた。大変興味深いことは、Ａサイトの混晶化により、ペロブスカイト量子ドット太陽電池の光電変換効率は12％ぐらいから約15％までに向上したことに成功した。さらに、ＡサイトはPQDの光励起キャリアダイナミクス、特にホットキャリアの緩和プロセスに大きな影響を与えることを見出した。さらに、カルボキシル基を持つ一連の半導体配位子を使用することにより、PQDからCoolキャリアとホットキャリア両方を効率的に抽出することが可能であることを発見した。光励起ホットキャリアダイナミクスを解析した結果、PQDのホットキャリアの冷却が大幅に延長され、ホットキャリアの抽出が容易になることが分かった。半導体リガンドとCsPbI3QDの間の化学結合、電子結合、およびキャリア移動は、ドナー-アクセプターシステムでは互いに共生していることが示唆された。これらの結果は、Coolとホットキャリアの抽出と太陽電池への利用を実現する要因に光を当て、多重励起子型とホットキャリア型太陽電池を設計するための戦略を提供できる。, 20H02565
01 Apr. 2020 - 31 Mar. 2023

鉛を含まないSn-ペロブスカイト太陽電池の高効率化指針提案
早瀬修二
2019 - 2021

錫ペロブスカイト光電変換素子の発電阻害機構解明とナノへテロ界面構築による高効率化
早瀬修二
Principal investigator
01 Apr. 2017 - 31 Mar. 2020

Direct observation of spin formation and charge accmulation in perovskite solar cells and the performance improvement
MARUMOTO Kazuhiro; HAYASE Shuji
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, University of Tsukuba, Grant-in-Aid for Challenging Exploratory Research, Perovskite solar cells have attracted much attention as a next-generation solar cell because they show high efficiency and can be fabricated at a low-cost fabrication process. In this study, we have directly observed spin and charge states in perovskite solar cells under device operation using electron spin resonance spectroscopy from a microscopic viewpoint in order to elucidate the degradation mechanism of the cells. As a result, we have found the correlation between the spin-charge states and the degradation of the device performance, and have clarified the origin of the degradation mechanism of the cells. Such elucidation of the correlation between the spin-charge states and the performance degradation at the molecular level would give deep insight into the operation mechanism of the cells and would be useful for further improvement of the device performance., 15K13329
01 Apr. 2015 - 31 Mar. 2018

Trap distribution analysis for thermal stimulation current of tin-based perovskite thin film
Ogomi Yuhei; SHEN Qing; IIKUBO Satoshi; HAYASE Shuzi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kyushu Institute of Technology, Grant-in-Aid for Young Scientists (B), Focus has been directed for tin-based perovskite films as a substitute for most widely studied lead halide perovskites. This research has investigated the relationship between crystal growth control of tin-based perovskite along with defect analysis and its implications on the solar cell performance. We have demonstrated a profound enhancement of the short circuit current from 20 mA/cm2 to 30 mA/cm2 using SnI2 complex for the fabrication of tin-halide perovskite as material. It has been found that when TiO2 as electron transporting material and SnI2 were chemically bonded, there was an increase in the TiO2 surface traps. Therefore, efforts were directed to prepare the tin-based perovskite solar cells without using TiO2 which led to the improved device performance. The absorption wavelength was changed by partially replacing the iodine by bromine. SnF2 was also doped in order to supplement metal defects. The conversion efficiency of the solar cell improved from 4.5% to 15.9%., 15K21224
01 Apr. 2015 - 31 Mar. 2017

In-situ measurement of perovskite crystal growth and the solar cell efficiency.
HAYASE SHUZI
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kyushu Institute of Technology, Grant-in-Aid for Challenging Exploratory Research, This report deals with the relationship between perovskite(Pb-PVK) solar cell efficiency and the crystal structure affected by nano-pore walls. Crystal structures of perovskite (Pb-PVK) created in the TiO2 nano-pore was smaller than that of the bulk Pb-PVK and were affected by the wall structures passivated with thin Al2O3, Y2O3 and ZrO2 layer. Crystal defect density was also affected by the surface structure. The presence of chloride anion increased the crystal size as well as the grain size. In addition, density of Ti-O-Pb linkages which present at the hetero-interface between the Pb-PVK layer and nano-pore wall of TiO2 and work for decreasing charge recombination centers, was enhanced by the presence of the chloride anion. The above results explain the efficiency enhancement of the solar cell in the presence of chloride anion. It was found that nano-pore wall structure is one of the factors for determining the efficiency., 15K13774
01 Apr. 2015 - 31 Mar. 2017

Carrier diffusions and their electronic states at interfaces in perovskite solar cells
Kobori Yasuhiro; HAYASE SHUJI; OGOMI YUHEI
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kobe University, Grant-in-Aid for Challenging Exploratory Research, In recent years, great attentions have been attracted on the perovskite solar cells as the next generation thin-film photovoltaics that can be low-cost, flexible and light. In this study, we observed photoinduced separated charges in the photoactive layers in the perovskite (CH3NH3PbI3) solar cells by using the time-resolved electron paramagnetic resonance spectroscopy for the three layer thin films (Spiro-OMeTAD/CH3NH3PbI3/TiO2 on a glass substrate) composed of the organic hole transport layer (Spiro-OMeTAD), the CH3NH3PbI3 layer and the mesoporous TiO2 fabricated by spin coating method on the mesoporous TiO2 films. We have characterized the spin density distributions of the trapped holes of the CH3NH3PbI3 layer at 110 K. Furthermore, from the ESP generated in the trapped hole, we have estimated the J coupling in the primary electron-hole pairs which will give us an insight on the electronic coupling of the Wannier excitons., 26620065
01 Apr. 2014 - 31 Mar. 2017

Investigation of suitable dye molecular framework focusing small driving force for electron injection and dye regeneration in NIR dyes for efficient photoconversion
PANDEY SHYAM S.
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kyushu Institute of Technology, Grant-in-Aid for Scientific Research (C), Combined theoretical and experimental approaches have been applied for the design and development of novel sensitizing dyes aiming towards the NIR photon harvesting. Utilizing a model far-red sensitive squaraine dye, TD-DFT theoretical calculations were performed to optimize the best calculation parameters giving minimum possible error between the calculated and experimental values of the energetics and electronic absorption spectrum. Optimization of calculation parameters gave only an error of 0.1 eV for the energy of HOMO and 40-60 nm in the absorption maximum tested for a series of squaraine dyes. It has also been found that it is possible to have facile electron injection and dye regeneration with the minimum energy barrier of 0.15 eV and 0.12 eV, respectively. This led to conclude that it is possible to design novel sensitizers having photon harvesting up to 1060 nm., 26410206
01 Apr. 2014 - 31 Mar. 2017

Nano-interface engineering of heterojunction quantum dot solar cells and the effect on charge separation of multiple excitons
Shen Qing; HAYASE Shuzi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), As one candidate of the next generation solar cells, colloidal quantum dot (CQD) based solar cells (CQDSCs) have attracted considerable interest and developed rapidly during the last few years. CQDSCs have some unique advantages such as the band-gap tunability, high absorption coefficient, multiple exciton generation (MEG) possibility and low cost for preparation. Although theoretical energy conversion efficiency of CQDSCs has been predicted to be about 44% much higher than the Shockley-Queisser limit (33%), it is still about 8% at present time (2014). Therefore, fundamental studies on the mechanism for improving energy conversion efficiency of CQDSCs are very important. In this project, we focus on clarifying the photoexcited carrier dynamics, especially the dynamics of MEG and improving the charge separation and suppress recombination in QD heterojunction solar cells by controlling the interfaces of CQDSCs as well as the approaches to improving the energy conversion efficiency., 26286013
01 Apr. 2014 - 31 Mar. 2017

Proposal of photoelectric conversion device structures fabricated by merging molecular diffusion engineering in continuous nanopores and photoelectron conversion interface engineering
HAYASE Shuzi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kyushu Institute of Technology, Grant-in-Aid for Scientific Research (B), Our objective is to propose items which are necessary to increase efficiency of dye-sensitized solar cells from the view point of diffusion of redox species in TiO2 nanopores whose wall is stained by dye molecules. When wall of nano pores was stained by dyes having similar size of substituents, diffusion of redox species in nanopores stained with dyes bearing polar substituents became low and open circuit voltage was low. This was explained by facile charge recombination between slowly diffused redox speciesand TiO2 electrons in nanopores. Dyes with hydrophobic long alkyl groups are proposed to be preferable for dye-sensitized solar cells with high open circuit voltage from the view point of redox diffusion in nanopores stained by dyes., 21350079
2009 - 2012

酸化物半導体ナノホールアレイからの電気化学発光と波長制御
早瀬 修二
日本学術振興会, 科学研究費助成事業, 九州工業大学, 萌芽研究, 本テーマの目的はナノスペースからの発光を利用し、電気化学発光の高効率化を図ることおよびその波長をナノ構造によって制御可能かどうかを検証することである。電気化学発光種にはRu錯体を用いた。Ru錯体の酸化体と還元体が衝突することにより励起Ru錯体が生成し、これが基底状態に戻るときに発光が観察される。昨年はチタニアのナノホールアレイを用い、ナノホールでの限られた空間でRu錯体酸化体と還元体の衝突頻度を増大することによって、発光強度を増大させることに成功した。今年は、チタニアナノホールアレイより作製が容易で大面積作製が可能なZnOナノロッドアレイを電極に用いた。ZnOナノロッドアレイ間のナノ空間からの電気化学発光を観察し、ナノ空間を使った発光強度増大を検討した。素子は、透明導電膜基板/酸化亜鉛ナノドットアレイ/Ru錯体溶液/透明導電膜基板からなる。素子に交流を印加したところ、平板の電極に比べ10倍以上の大きな発光の増大が見られた。さらに特徴的なことは、発光開始電圧が平板電極型素子の2.5-3Vに比較し酸化亜鉛ナノロッドを使ったセルでは1.5Vと大きく低電圧化できたことである。ZnOナノロッドの長さを4.0ミクロンから8.1ミクロン、11.5ミクロンと長くすると、さらに発光強度の増大が見られた。発光の時間分解特性を詳細に検討することにより反応のメカニズムを検討した。負の電位から正の電位に変化したときにミリ秒の時間スケールで大きな発光が持続することがわかった。これはZnOナノロッドから電子が注入されてナノスペースに生成した多量のRu錯体還元体(負極)が、電極の極性が変わった後で(正極)、酸化亜鉛ナノロッド底部の透明導電膜基板で生成したRu錯体酸化体がナノスペース中を煙突として移動し、効率よくナノスペース中でRu酸化体と還元体が衝突するためと考えられた。このようにナノスペースを用いた発光現象を利用することによって、電気化学発光の低電圧発光、発光の高効率化が可能になることを実証できた。, 19655070
2007 - 2008

Low temperature fabrication of electron-nano-path and the performance of the solar cell consisting of the bi-continuous nano-path.
HAYASE Shuzi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kyushu Institute of Technology, Grant-in-Aid for Scientific Research (B), The improvement of the photovoltaic performance for dye sensitized solar cells prepared at low temperatures was discussed from the view point of the fabrication of nano-paths for electrons and ions in the TiO_2 electrodes. The effect of ionic diffusions in the TiO_2 nano-porous electrodes on the solar cell performance was simulated by using a new model. It was concluded that the retardation of the ionic diffusions in the TiO_2 electrode causes the deterioration of the solar cell performance. The results suggested that the nano-pores have to be designed well. In order to improve the ionic diffusions in the TiO_2 nano-porous electrode, TiO_2 electrodes consisting of fractal like structures were fabricated by the electro-spray deposition of TiO_2 nano-particles on the conductive substrate. The short circuit current (Jsc) increased due to the increase in ionic diffusion coefficients in the nano-pores, which was consistent with the simulation results. In addition, we found that the addition of needle like TiO_2 help increase the ionic diffusions in the TiO_2 nano-porous electrodes. The addition of the needle increased the Jsc. Another approach for the improvement is to make electron paths at low temperature. We focused on TiO_2 grain boundary. Low V acceleration electron beam exposure (LVEB) which does not damage the substrate because of the low voltage was tried at room temperature. After the LVEB exposure, the increases in the electron diffusion coefficient and Jsc were observed, suggesting that the LVEB is useful for linking the boundary at low temperatures. The dye-staining of TiO2 surface under CO_2 super critical conditions increased Jsc because of the increase in the surface coverage of the nano-porous TiO_2 electrode. However, the surface trap passivation with dye molecules did not increase the electron diffusion coefficient because on the traps remaining at the interface of the grain boundary. This contrasted the results of DSCs prepared at 450℃., 15350112
2003 - 2006

Highly Efficiency Solar Energy Conversion Using Photointerface System
FUJISHIMA Akira; MURAKAMI Taketoshi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research on Priority Areas, Toward important technical developments in the effective use of solar energy, many devices by the application of photofunctional interface based on TiO2 have been investigated. In this research, we had investigated the followings that were particularly considered as playing the major roles in such devices. -Development of Fabrication Process of Dye-Sensitized Solar Cell: With regard to wet-type dye-sensitized solar cells, there have been practical problems in terms of stability and durability due to the use of an electrolyte. To solve the problems, we fabricated a complete-solid-type dye-sensitized solar cell by using CuI as a p-type semiconductor in place of an electrolyte. Triethylamine hydro-thiocyanate was used as a grain refiner of CuI crystal. With this complete-solid-type dye-sensitized solar cell made by using a CuI automatic application device, photovoltaic conversion efficiency with reproducibility was achieved. -Research on Low Reflectance Self-Cleaning Glass: The utilization of self-cleaning properties of photocatalyst for preventing stains on glass is disadvantageous in that the light transmittance of glass is reduced due to a high refractive-index and light reflectivity of TiO2. In order to solve this problem, we developed a low-reflectance self-cleaning glass using SiO2 particles and TiO2 nanoparticles. As a result, we succeeded in coating a glass substrate with a TiO2-SiO2 double layer, which showed a high self-cleaning function as well as a maximum light transmittance of 97% or higher. -Research on Water Purification Reactor using Photocatalyst: A photocatalyst water purification reactor can treat 10 liters of water at a time. It can also be used in continuous water flow. With this reactor, the degradation of thionine solution having reproducibility was confirmed. -Research on TiO2 Nano-Fiber: TiO2-SiO2 nano composite fiber is an excellent material that is expected to have high photocatalyst property, heat stability, and low thermal expansion. In this research, TiO2-SiO2 nano composite fiber was researched and developed on the basis of a new adjustment method that used P-25 (Nippon Aerosil) as Ti source and TEOS (Tetraethoxy-silane)-PDMS (Polydimethylsiloxane) sol composite as Si cource. By implanting TiO2 nanoparticles into a SiO2 fiber based on this method, we succeeded in developing a TiO2-SiO2 nano composite fiber having a diameter of 500-700nm and consisting of a TiO2-SiO2 linear complex chain with high mechanical strength., 14050023
2002 - 2006

High efficiency quasi-solid dye sensitized solar cells consisting of organic-inorganic hybrid ionic paths
HAYASE Shuzi
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Kyushu Institute of Technology, Grant-in-Aid for Scientific Research on Priority Areas, Solidification of dye sensitized solar cells (DSC) is one of the most crucial research items. Solidification generally decreases ionic diffusion and lower the solar cell efficiency. Because of this, quasi-solidification is one of the most promising candidates for the solidification. However, quasi-solidified DSCs reported so far are soft gel and the solidification ratio (solid part/all carrier layer) was less than 10-20% because the high solidification ratio lowers the efficiency. Our purpose is to propose high efficiency quasi-solid DSCs with high solid content more than 50% (so-call high solid type quasi-solid DSCs). In this research program, we proposes hybrid quasi-solid DSCs consisting of a high carrier density layer and a low carrier density layer. The former fills the bulk layer between a TiO_2 layer and a counter electrode and the latter fills the nano-pores in TiO_2 layers. The former brings about high conductivities in the solid state layer (bulk layer) and the latter prevents back electron transfer from the TiO_2 to carrier layer. The proposal was realized by three cell structures, namely, surface modified porous Al_2O_3/ionic liquid type electrolyte, surface modified nano-oxide materials/ionic liquid type electrolyte, and a composite carrier transport layer consisting of porous Al_2O_3 membrane/conductive polymer/ionic liquid type electrolyte. In all cases, carriers were concentrated in the surface-modified nano-structured materials, resulting in making high carrier concentration areas. The photovoltaic properties of the high solid type solar cells (solidification ratio/more than 50%) were almost the same as or higher than those of the cells before the solidification. It was proved that the hybrid solar cells consisting of two carrier concentration layers are effective structure having high photovoltaic properties and the idea has generality for fabricating high efficiency solid solar cells., 17029051
2001 - 2006

擬固体電解質とナノチタニア層との界面最適化による擬固体色素増感太陽電池の高性能化
早瀬 修二
日本学術振興会, 科学研究費助成事業, 九州工業大学, 特定領域研究, 色素増感太陽電池(DSSC)は揮発性有機溶剤を含んだ電解液を使用しており、耐久性を確保するには十分な封止技術が必要である。我々は不揮発性の室温溶融塩をゲル化することにより電解質を固体化する技術が耐久性向上に有効であることを実証してきた。しかし室温溶融塩は有機溶剤タイプの電解液に比較し粘度が高くイオンの拡散定数が低いという欠点があった。限界電流を大きくするため電荷輸送体であるヨウ素の濃度を有機溶剤系電解液より10倍程度高くする必要があった。このため暗電流が大きくなり太陽電池性能の低下がしばしば見られた。チタニア界面を修飾して逆電子移動を抑制する試みが従来の溶剤系電解液で試みられてきた。しかしSnO_2を半導体電極に使った場合には大きな性能向上効果が報告されているがチタニアを使った場合には効果は小さいと報告されている。我々は溶融塩を電解液とするDSSCのチタニアナノ界面を修飾しその効果を調べた。チタニアナノ界面は色素分子で覆われているが、その隙間から逆電子移動が起こる。色素の間を埋めるblocking materialとして、(1)チタニア表面と反応しやすい、(2)色素の間を埋めることができるように分子が小さいなどの理由から、カルボン酸を選んだ。チタニア界面を酢酸でブロックしたチタニア電極を用いたDSSCは、未処理のDSSCに比較し短絡電流が8mA/cm2から13mA/cm2と大きく向上した。界面修飾は室温溶融塩を使ったDSSCの効率向上に非常に有効である。, 14050077
2002 - 2002