Prof. Shuzi Hayase Profile

Prof. Shuzi Hayase

Professor at Univ of Electro-Communications

SPIE Involvement:

Editorial Board Member: Journal of Photonics for Energy | Author

Publications (19)

Proceedings Article | 1 October 2023 Presentation + Paper

Tin based perovskite solar cells and all-perovskite tandem solar cells

Shuzi Hayase, Liang Wang, Takeshi Kitamura, Huan Bi, Gaurav Kapil, Hiroshi Segawa, Saulius Grigalevicius

Proceedings Volume 12660, 1266005 (2023) https://doi.org/10.1117/12.2678067

KEYWORDS: Tin, Solar cells, Perovskite, Tandem solar cells, Metals, Plasma treatment, Oxygen, Oxides, Nanoparticles, Lead

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SPIE Journal Paper | 2 December 2022

Cylindrical transparent conductive oxide-free dye-sensitized solar cells with treated flat titanium sheet

Azwar Hayat, Ajay Kumar Baranwal, Masaki Nakamura, Fujisawa Shigeki, Shyam Pandey, Shuzi Hayase

JPE, Vol. 12, Issue 04, 045502, (December 2022) https://doi.org/10.1117/12.10.1117/1.JPE.12.045502

KEYWORDS: Dye sensitized solar cells, Titanium, Dyes, Solar cells, Electrodes, Glasses, Transparent conductors, Nanosheets, Electrolytes, Photons

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Proceedings Article | 1 August 2021 Presentation

Band engineering of Sn and SnPb perovskite solar cells for efficiency enhancement

Gaurav Kapil, Muhammad Akmal Kamarudin, Kohei Nishimura, Daisuke Hirotani, Qing Shen, Satoshi Iikubo, Mengmeng Chen, Zhang Zheng, Shuzi Hayase

Proceedings Volume 11809, 118090B (2021) https://doi.org/10.1117/12.2594973

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SPIE Journal Paper | 9 November 2020

Effect of electrolyte for back contact transparent conducting oxide-less dye-sensitized solar cells: iodine versus cobalt

Md. Zaman Molla, Ajay Kumar Baranwal, Shuzi Hayase, Shyam Pandey

JPE, Vol. 10, Issue 04, 045501, (November 2020) https://doi.org/10.1117/12.10.1117/1.JPE.10.045501

KEYWORDS: Dye sensitized solar cells, Solar energy, Cobalt, Electrodes, Photovoltaics, Photons, Iodine, Transparent conductors, Quantum efficiency, Resistance

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Proceedings Article | 20 August 2020 Presentation

Pb free Sn- perovskite solar cells with over 13% efficiency

Kohei Nishimura, Muhammad Akmal Kamarudin, Daisuke Hirotani, Qing Shen, Takashi Minemoto, Kenji Yoshino, Shuzi Hayase

Proceedings Volume 11474, 114740X (2020) https://doi.org/10.1117/12.2566181

KEYWORDS: Solar cells, Perovskite, Lead, Tin, Germanium, Ions, Energy efficiency, Electron transport, Crystals

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Proceedings Article | 18 September 2018 Presentation

Pb free perovskite solar cells consisting of mixed metal SnGe perovskite as light absorber (Conference Presentation)

Shuzi Hayase, Nozomi Ito, Muhammad Akmal Kamarudin Kamarudin, Qing Shen, Yuhei Ogomi, Satoshi Iikubo, Kenji Yoshino, Takashi Minemoto, Taro Toyoda

Proceedings Volume 10737, 107371F (2018) https://doi.org/10.1117/12.2321061

KEYWORDS: Perovskite, Solar cells, Lead, Metals, Germanium, Tin, Doping, Solar energy, Chemical species, Photovoltaics

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Despite the high-efficiency of these lead-based perovskite solar cells, the problem associated from the toxic nature of lead has open a new research direction which focuses on lead-free perovskite materials. As an alternative, tin has been proposed to replace lead. The highest efficiency obtained with Sn only perovskite was 9 % which was based on 2D and 3D mixture of FASnI3. However, Sn-based perovskites are known to have low stability in air. The use of germanium-based perovskite in solar cell was first realized by Krishnamoorthy et. al. The measured solar cell performance was notably low, 0.11 % for CsGeI3 and 0.20 % for MAGeI3. A theoretical study exploring hybrid tin and germanium perovskite showed that it is possible to prepare a stable Sn-Ge perovskite material that absorbs the sunlight spectrum. In this study, a new type of SnGe mixed metal perovskite solar cells are reported with enhanced efficiency and stability. In this report, FA0.75MA0.25Sn1-xGexI3 (abbreviated as SnGe(x)-PVK) were used for the mixed metal SnGe perovskite. XRD spectra showed that the structure is perovskite. The structure of Ge-doped Sn perovskite was also discussed from the view point of band gap, conduction and valence band level, XPS analysis, and the urbach energy. It can be concluded that most of the Ge atoms passivate the surface of the Sn perovskite (graded structure).For SnGe(0)-PVK device, the averageJsc was 17.61 mA/cm2, VOC was 0.46 V, FF was 0.41 and PCE of 3.31 %. Upon doping with 5 wt% of Ge, the JSC increased up to 19.80 mA/cm2, FF improved up to 0.55 with an overall efficiency of 4.48 %. Upon increasing the Ge content more than 10wt%, all the photovoltaic parameters decreased significantly which resulted in an efficiency as low as 0.80 % for SnGe(0.2)-PVK device. After optimization, 7.75% of SnGe(5)-PVK device is reported. Significant effect on Ge doping was seen in the enhancement of the stability. The stability in air has been improved significantly with the Ge doping, retaining 80 % of its original performance, remarkable stability enhancement, compared with 10 % retention for non-doped sample. This work provides a platform for further research on lead-free Sn-Ge based perovskite solar cells.

SPIE Journal Paper | 9 March 2018

Interparticle coupling effect of silver-gold heterodimer to enhance light harvesting in ultrathin perovskite solar cell

Zhaosheng Hu, Tingli Ma, Shuzi Hayase

JPE, Vol. 8, Issue 01, 015502, (March 2018) https://doi.org/10.1117/12.10.1117/1.JPE.8.015502

KEYWORDS: Perovskite, Absorption, Gold, Metals, Silver, Solar cells, Plasmons, Light harvesting, Nanoparticles, Radiation effects

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Proceedings Article | 19 September 2017 Presentation

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

Proceedings Volume 10363, 1036313 (2017) https://doi.org/10.1117/12.2274760

KEYWORDS: Interfaces, Solar cells, Metals, Light harvesting, Photovoltaics, Tin, Lead, Infrared radiation, Absorption, Computer architecture

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SPIE Journal Paper | 13 January 2017

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 Pandey, Tingli Ma, Shuzi Hayase

JPE, Vol. 7, Issue 01, 015501, (January 2017) https://doi.org/10.1117/12.10.1117/1.JPE.7.015501

KEYWORDS: Dye sensitized solar cells, Titanium, Electrodes, Transparent conductors, Glasses, Interfaces, Photovoltaics, Resistance, Coating, Quantum efficiency

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Proceedings Article | 2 November 2016 Presentation

Interface architecture between TiO2/perovskite, perovskite/hole transport layer, and perovskite grain boundary (Conference Presentation)

Shuzi Hayase, Daisuke Hirotani, Masahiro Moriya, Yuhei Ogomi, Qing Shen, Kenji Yoshino, Taro Toyoda

Proceedings Volume 9942, 99420G (2016) https://doi.org/10.1117/12.2238530

KEYWORDS: Interfaces, Sensors, Adsorption, Chlorine, Crystals, Solar cells, Computer architecture, Quartz, Titanium dioxide, Perovskite

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In order to examine the interface structure of TiO2/perovskite layer, quartz crystal microbalance sensor (QCM) was used. On the QCM sensor, TiO2 layer was fabricated and the PbI2 solution in Dimethylformamide (DMF) was passed on the QCM sensor to estimate the adsorption density of the PbI2 on the titania2. The amount of PbI2 adsorption on TiO2 surface increased as the adsorption time and leveled off at a certain time. PbI2 still remained even after the solvent only (DMF) was passed on the TiO2 layer on QCM (namely rinsing with DMF), suggesting that the PbI2 was tightly bonded on the TiO2 surface. The bonding structure was found to be Ti-O-Pb linkage by XPS analysis. We concluded that the Ti-OH on the surface of TiO2 reacts with I-Pb-I to form Ti-O-Pb-I and HI (Fig.1 B). The surface trap density was measured by thermally stimulated current (TSC) method. Before the PbI2 passivation, the trap density of TiO2 was 1019 cm3. The trap density decreased to 1016/cm3 after the PbI2 passivation, suggesting that the TiO2 surface trap was passivated with I-Pb-I. The passivation density was tuned by the concentration of PbI2 in DMF, by which TiO2 layer was passivated. Perovskite solar cells were fabricated on the passivated TiO2 layer with various PbI2 passivation densities by one step process (mixture of PbI2 + MAI in DMF). It was found that Jsc increased with an increase in the Ti-O-Pb density. We concluded that the interface between TiO2 and perovskite layer has passivation structure consisting of Ti-O-Pb-I which decreases the trap density of the interfaces and supresses charge recombination. The effect of Cl anion on high efficiency is still controversial when perovskite layer is prepared by one step method from the mixture of MAI and PbCl2. It was found that adsorption density of PbCl2 on TiO2 surface was much higher than that of PbI2 from the experiment using QCM sensor. After the surface was washed with DMF, Cl and Pb were detected. These results suggest that the TiO2 surface was much more passivated by PbCl2 than by PbI2. This may explain partially the high efficiency when the perovskite layer was fabricated by one step process consisting of MAI and PbCl2 solution. We also observed that the crystal size increased with an increase in the amount of Cl anion which of course one of the explanation of the high efficiency. The interface of hole transport layer/perovskite layer, and between perovskite layer /perovskite layer (grain boundary) was passivated with organic amines. The passivation was also effective for increasing Voc and Jsc. This was explained by the results of transient absorption spectroscopy that the charge recombination time between hole transport payer/perovskite layer increased from 0.3 μsec to 60 μsec.

SPIE Journal Paper | 25 March 2015 Open Access

Interface structure between titania and perovskite materials observed by quartz crystal microbalance system

Soya Nakayashiki, Hirotani Daisuke, Yuhei Ogomi, Shuzi Hayase

JPE, Vol. 5, Issue 01, 057410, (March 2015) https://doi.org/10.1117/12.10.1117/1.JPE.5.057410

KEYWORDS: Lead, Solar cells, Interfaces, Adsorption, Crystals, Electrons, Quartz, Sensors, Photovoltaics, Perovskite

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Proceedings Article | 20 November 2014 Paper

Sn halide based perovskite sensitized solar cells covering up to 1060 nm (presentation video)

Yuhei Ogomi, Atsushi Morita, Shota Tsukamoto, Takahiro Saito, Naotaka Fujikawa, Shen Qing, Taro Toyoda, Kenji Yoshino, Shyam Pandey, Tingli Ma, Shuzi Shuzi Hayase

Proceedings Volume 9184, 91840S (2014) https://doi.org/10.1117/12.2061065

KEYWORDS: Tin, Video, Solar cells, Solar energy, Near infrared, Polymers, Semiconductors, Quantum efficiency, Organic photovoltaics, Perovskite

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Proceedings Article | 13 September 2012 Paper

Dye adsorption feature on titania surface and role of dye aggregation inhibitor monitored by quartz crystal microbalance (QCM)

Ryohei Hirota, Yuhei Ogomi, Shyam Pandey, Shuzi Hayase

Proceedings Volume 8477, 847712 (2012) https://doi.org/10.1117/12.929235

KEYWORDS: Adsorption, Crystals, Dye sensitized solar cells, Solar cells, Quartz, Sensors, Dysprosium, Amorphous silicon, Silicon, Titanium dioxide

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SPIE Journal Paper | 17 May 2012

Flexible transparent conductive oxide-less flat and cylinder dye-sensitized solar cells

Jun Usagawa, Takeshi Kogo, Kengo Sadamasu, Shyam Pandey, Yuhei Ogomi, Shuzi Hayase

JPE, Vol. 2, Issue 1, 021011, (May 2012) https://doi.org/10.1117/12.10.1117/1.JPE.2.021011

KEYWORDS: Dye sensitized solar cells, Electrodes, Electrons, Solar cells, Silicon, Photovoltaics, Metals, Particles, Quantum efficiency, Positron emission tomography

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Proceedings Article | 21 September 2011 Paper

Fine tuning the structure of unsymmetrical squaraine dyes towards the development of efficient dye-sensitized solar cells

Shyam Pandey, Rie Watanabe, Naotaka Fujikawa, Yuhei Ogomi, Yoshihiro Yamaguchi, Shuzi Hayase

Proceedings Volume 8111, 811116 (2011) https://doi.org/10.1117/12.893354

KEYWORDS: Dye sensitized solar cells, Absorption, Adsorption, Solar energy, Solar cells, Molecular aggregates, Dysprosium, Mass attenuation coefficient, Photovoltaics, Titanium dioxide

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SPIE Journal Paper | 1 January 2011 Open Access

Transparent conductive oxideless tandem dye-sensitized solar cells consisting of light-splitting structures

Jun Usagawa, Masaki Kaya, Yuhei Ogomi, Shyam Pandey, Shuzi Hayase

JPE, Vol. 1, Issue 1, 011110, (January 2011) https://doi.org/10.1117/12.10.1117/1.3555458

KEYWORDS: Dye sensitized solar cells, Electrodes, Glasses, Mirrors, Waveguides, Solar cells, Photovoltaics, Transparent conductors, Particles, Light scattering

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Proceedings Article | 27 September 2007 Paper

Dye-sensitized solar cells with high efficiency: from interface control to solidification

Yuhei Ogomi, Shohei Sakaguchi, Shuzi Hayase

Proceedings Volume 6656, 665606 (2007) https://doi.org/10.1117/12.732354

KEYWORDS: Dye sensitized solar cells, Electrodes, Photovoltaics, Diffusion, Solids, Aluminum, Molecules, Carbon monoxide, Solar cells, Adsorption

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Proceedings Article | 6 February 2004 Paper

Quasi-solid dye-sensitized solar cells: control of TiO2-gel electrolyte interfaces

Shuzi Hayase, Takehito Kato, Takashi Kado, Shohei Sakaguchi, Hirotaka Ueki, Wataru Takashima, Keiichi Kaneto, Ryuichi Shiratuchi, Hiroyasu Sumino, Shinji Murai, Satoshi Mikoshiba

Proceedings Volume 5215, (2004) https://doi.org/10.1117/12.505564

KEYWORDS: Liquids, Dye sensitized solar cells, Molecules, Diffusion, Interfaces, Electrodes, Particles, Solar cells, Carbon, Solids

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Proceedings Article | 11 June 1999 Paper

Application of polysilanes for deep-UV antireflective coating

Yasunobu Onishi, Yasuhiko Sato, Eishi Shiobara, Seiro Miyoshi, Hideto Matsuyama, Junko Abe, Hideo Ichinose, Tokuhisa Ohiwa, Yoshihiko Nakano, Sawako Yoshikawa, Shuzi Hayase

Proceedings Volume 3678, (1999) https://doi.org/10.1117/12.350203

KEYWORDS: Etching, Deep ultraviolet, Dielectrics, Coating, Interfaces, Refractive index, Antireflective coatings, Photoresist materials, Reflectivity, Reflection

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Showing 5 of 19 publications

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