Hiroyuki Toyota

(豊田裕之)

Profile Information

Affiliation: Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

Degree: Ph. D(Mar, 2005, The University of Tokyo)

Researcher number: 00415895
J-GLOBAL ID: 202101003284515547
researchmap Member ID: R000016575

Research Interests

Research Areas

Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Electrical power engineering / Power Systems for Space Application

Research History

Apr, 2005 - Present

Associate Professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

Education

Apr, 2000 - Mar, 2005

Department of Electrical Engineering, The Graduate School of Engineering, The University of Tokyo
Apr, 1996 - Mar, 2000

Department of Electrial Engineering, The Faculty of Engineering, The University of Tokyo
Apr, 1993 - Mar, 1996

Eiko Gakuen High School
Apr, 1990 - Mar, 1993

Eiko Gakuen Junior High School
Apr, 1984 - Mar, 1990

Okamura Elementary School

Papers

Design, testing, and analytical characterization of a low-hysteresis linkage-actuated re-deployable radiator for deep space missions

Yuki Akizuki, Kenichiro Sawada, Tomihiro Kinjo, Hiroyuki Ogawa, Toshiaki Okudaira, Hiroyuki Toyota, Kazutaka Nishiyama, Hiroshi Imamura, Takeshi Takashima, Kan Matsumoto, Takeshi Kuratomi, Kazuki Watanabe, Hosei Nagano

Applied Thermal Engineering, 291 130129-130129, Apr, 2026 Peer-reviewed
In-orbit Operation of CubeSat Moon Lander OMOTENASHI

Tatsuaki HASHIMOTO, Junji KIKUCHI, Ryo HIRASAWA, Shintaro NAKAJIMA, Naoki MORISHITA, Atsushi TOMIKI, Wataru TORII, Masatsugu OTSUKI, Tetsuo YOSHIMITSU, Yasuo ISHIGE, Kota MIYOSHI, Nobutaka BANDO, Chikako HIROSE, Hiroshi TAKEUCHI, Hiroyuki TOYOTA, Keiichi HORI, Kakeru TOKUNAGA, Aiko NAGAMATSU, Hitoshi MORIMOTO, Toshinori IKENAGA, OMOTENASHI project team

Journal of Evolving Space Activities, 3, Aug, 2025 Peer-reviewed
In Situ Evaluation of Perovskite Solar Cells after 8 MeV Proton Irradiation at Low Temperatures

Yu Miyazawa, Naoyuki Shibayama, Masashi Ikegami, Tsutomu Miyasaka, Ryoya Ishigami, Shusaku Kanaya, Hiroyuki Toyota, Kazuyuki Hirose

The Journal of Physical Chemistry C, Jul 8, 2025 Peer-reviewed
Moon Landing Results of SLIM : A Smart Lander for Investigating the Moon

Shinichiro Sakai, Kenichi Kushiki, Shujiro Sawai, Seisuke Fukuda, Yu Miyazawa, Takayuki Ishida, Kazuki Kariya, Takahiro Ito, Satoshi Ueda, Kentaro Yokota, Taro Kawano, Makiko Ohtake, Kazuto Saiki, Yusuke Nakauchi, Keisuke Michigami, Katsumi Furukawa, Yuki Akizuki, Shusaku Kanaya, Tomihiro Kinjo, Kenta Goto, Kenichiro Sawada, Yoshihide Sugimoto, Hiroshi Takeuchi, Atsushi Tomiki, Hiroyuki Toyota, Taiichi Nagata, Junichi Nakatsuka, Kenichiro Maki, Takahide Mizuno, Hirohide Shiratori, Masaki Nishino, Naoto Usami, Junji Kikuchi, Hitoshi Hamori, Ryo Hirasawa, Yusuke Shibasaki, Hiroaki Saito

Acta Astronautica, May, 2025 Peer-reviewed
Thermal and Mechanical Design of Thin-Film Solar Arrays on Textile Origami Deployable Structures

So Yeon Suk, Atsuki Ochi, So Tanaka, Delburg P. Mitchao, Mitsuhiko Yasuhara, Takashi Tomura, Hiraku Sakamoto, Osamu Mori, Hiroyuki Toyota, Yu Miyazawa, Shusaku Kanaya, Masanori Matsushita, Tamotsu Horiuchi, Ryota Takabe, Yuko Hisada, Rie Tokuda, Kenta Noguchi

AIAA SCITECH 2025 Forum, Jan 3, 2025
Operational Results of Li-ion Pouch Battery Cells Using Stainless-Steel Laminated Film for SLIM

Hiroyuki Toyota, Yu Miyazawa, Shusaku Kanaya, Akio Kukita, Hitoshi Naito, Hiroatsu Kondo, Kazuya Koide, Kenichi Kushiki, Seisuke Fukuda, Shujiro Sawai, Shinichiro Sakai

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 24(SLIM) s44-s52, 2025 Peer-reviewedLead author
Development and On-orbit Operation of Solar Panels for JAXA's Lunar Lander SLIM (Smart Lander for Investigating Moon)

Shusaku Kanaya, Yu Miyazawa, Hiroyuki Toyota, Tetsuya Nakamura, Taishi Sumita, Akio Kukita, Shujiro Sawai, Seisuke Fukuda, Kenichi Kushiki, Shinichiro Sakai

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 24(SLIM) s37-s43, 2025 Peer-reviewed
Results of SLIM Developments and Operations

Shinichiro Sakai, Kenichi Kushiki, Shujiro Sawai, Seisuke Fukuda, Yu Miyazawa, Satoshi Ueda, Takahiro Ito, Kentaro Yokota, Takayuki Ishida, Kazuki Kariya, Takahide Mizuno, Keisuke Michigami, Kenta Goto, Katsumi Furukawa, Taro Kawano, Yusuke Maru, Atsushi Tomiki, Shusaku Kanaya, Hiroyuki Toyota, Tomihiro Kinjo, Yuki Akizuki, Kenichiro Sawada, Masaki N. Nishino, Ken-ichiro Maki, Yoshihide Sugimoto, Hiroshi Takeuchi, Tetsuo Yoshimitsu, Masatsugu Otsuki, Naoto Usami, Kent Yoshikawa

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 24(SLIM) s3-s12, 2025 Peer-reviewed
Verification and Flight Results of SLIMIntegrated Power Control Unit

Kentaro Yokota, Hiroyuki Toyota, Shusaku Kanaya, Yu Miyazawa, Takashi Tazawa, Hiroaki Saito, Kenichi Kushiki, Seisuke Fukuda, Shujiro Sawai, Shinichiro Sakai

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 24(SLIM) s53-s59, 2025 Peer-reviewed
Dynamic model and compensation circuit for solar array characteristics

Kentaro Yokota, Hiroyuki Toyota, Shusaku Kanaya, Yu Miyazawa

Solar Energy, 283(15), Oct 30, 2024 Peer-reviewed
Electrical Characterization of Solar Array Panels by Absolute Electroluminescence Intensity

Tetsuya NAKAMURA, Hidefumi AKIYAMA, Shusaku KANAYA, Yu MIYAZAWA, Hiroyuki TOYOTA, Shin-ichiro SAKAI

Journal of Evolving Space Activities, 2, Sep, 2024 Peer-reviewed
Development of Thin Perovskite Solar Cells for Balloon Experiments

Shusaku KANAYA, Hideyuki FUKE, Yu MIYAZAWA, Hiroyuki TOYOTA, Kazuyuki HIROSE, Ryoto FUNAYAMA, Masashi IKEGAMI

Journal of Evolving Space Activities, 1, Apr, 2024 Peer-reviewed
Flyby of asteroid Phaethon: the Sun’s son and the Geminids' mother! (1) - Overview and science of DESTINY PLUS -

Arai T., Kobayashi M., Ishibashi K., Yoshida F., Kimura H., Hirai T., Okamoto T., Hong P. K., Yamada M., Wada K., Senshu H., Akitaya H., Srama R., Krüger H., Marshall S., Sasaki S., Yabuta H., Ishiguro M., Nakamura T., Ohtsuka K., Watanabe J., Ito T., Ootsubo T., Abe S., Sekiguchi T., Urakawa S., Hiroi T., Beniyama J., Morota T., Tachibana S., Mikouchi T., Matsuura S., Ito M., Yamaguchi A., Noguchi T., Nakamura-Messenger K., Komatsu M., Komatsu G., Demura H., Hirata N., Kaneda H., Yanagisawa T., Kurosaki H., Tatsumi E., Yano H., Yoshikawa M., Ozaki N., Yamamoto T., Mochihara Y., Tokudome S., Toyota H., Nishiyama K., Imamura H., Takashima T.

Planetary People - The Japanese Society for Planetary Sciences, 33(1) 34-50, Mar 25, 2024
DESIGN AND EVALUATION OF DEPLOYABLE PEROVSKITE SOLAR ARRAYS ABOARD SMALL SPACECRAFT

So Yeon Suk, Motoki Moritani, Hiraku Sakamoto, Tamotsu Horiuchi, Ryota Takabe, Yuko Hisada, Rie Tokuda, Osamu Mori, Hiroyuki Toyota, Yu Miyazawa, Masanori Matsushita, Kazuki Nagai, Atsuki Ochi, Delburg Mitchao, Yuki Takeda, Mitsuhiko Yasuhara, Soma Saito, Takashi Tomura

Proceedings of ASME 2024 Aerospace Structures, Structural Dynamics, and Materials Conference, SSDM 2024, 2024
Flight Tests of Perovskite Solar Cell for Applications to Balloon Envelope

Hideyuki FUKE, Shusaku KANAYA, Yu MIYAZAWA, Hiroyuki TOYOTA, Kazuyuki HIROSE, Ryoto FUNAYAMA, Masashi IKEGAMI

Journal of Evolving Space Activities, 1, Dec, 2023 Peer-reviewed
Deep Space Exploration Technology Demonstrator DESTINY+

Hiroyuki TOYOTA, Takeshi TAKASHIMA, Hiroshi IMAMURA, Kazutaka NISHIYAMA, Takayuki YAMAMOTO, Takeshi MIYABARA, Masayuki OHTA, Yoshitaka MOCHIHARA, Naoya OZAKI, Hiroyuki NAGAMATSU, Takakazu OKAHASHI, Junko TAKAHASHI, Toshiaki OKUDAIRA, Takayuki HIRAI, Masanori KOBAYASHI, Ko ISHIBASHI, Peng HONG, Osamu OKUDAIRA, Tomoko ARAI

Journal of Evolving Space Activities, 1, Dec, 2023 Peer-reviewedLead author
Development of Lithium-Ion Pouch Cell Using Stainless-Steel Laminated Film for JAXA’s SLIM Lunar Lander

Hiroyuki TOYOTA, Yu MIYAZAWA, Shusaku KANAYA, Akio KUKITA, Hiroatsu KONDO, Kazuya KOIDE, Takahiro KUHARA, Kazuyuki NAKAMURA, Taro KAWANO, Hitoshi NAITO, Shujiro SAWAI, Seisuke FUKUDA, Shin-ichiro SAKAI

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 66(6) 199-208, Nov, 2023 Peer-reviewedLead author
On-orbit Demonstration of Lightweight Solar Array Paddles by DESTINY+ Spacecraft

Hiroyuki Toyota, Tetsuya Nakamura, Taishi Sumita, Shuraku Kanaya, Ryosuke Ono, Takeshi Miyabara, Takakazu Okahashi, Hiroshi Imamura, Takeshi Takashima, Ose Takayuki, Yukishige Nozaki, Takuro Kobayashi, Taichi Hirose, Naoyuki Kaneko, Hiroshi Yamaguchi

Proceedings of 13th European Space Power Conference, Oct, 2023 Lead author
Evaluation of hypervelocity impact of micrometeoroids and orbital debris on next-generation space solar cells

Hiroyuki Toyota, Tetsuya Nakamura, Shusaku Kanaya, Taishi Sumita, Takayuki Hirai, Masanori Kobayashi

Japanese Journal of Applied Physics, 62(SK) SK1047, Jun 8, 2023 Peer-reviewedLead author

Abstract This paper discusses the hypervelocity impacts of micrometeoroids and orbital debris (MMODs) on inverted metamorphic triple-junction (IMM3J) and perovskite solar cells, which are much thinner than conventional triple-junction (3J) solar cells. We experimentally found that IMM3J solar cells can suffer from short-circuit faults due to hypervelocity impacts of MMODs unlike conventional 3J cells, and determined the projectile diameters and velocities that could cause them using a model proposed by Burt. No short-circuit mode was identified in perovskite solar cells, but they had open-circuit faults several days after the hypervelocity impact experiment, which are possibly attributed to the decomposition of the perovskite crystal by moisture in the air due to the broken seal.
Lessons Learned from CubeSat Moon Lander OMOTENASHI

Tatsuaki Hashimoto, Junji Kikuchi, Ryo Hirasawa, Kota Miyoshi, Wataru Torii, Naoki Morishita, Nobutaka Bando, Atsushi Tomiki, Shintaro Nakajima, Masatsugu Otsuki, Hiroyuki Toyota, Kakeru Tokunaga, Chikako Hirose, Tetsuo Yoshimitsu, Hiroshi Takeuchi

Proceedings of the International Astronautical Congress, IAC, 2023-October, 2023
Systematic variation of photoluminescence spectra with donor and acceptor concentrations ranging from 1 × 1010 to 1 × 1020 cm−3 in Si

Michio Tajima, Hiroyuki Toyota, Atsushi Ogura

Japanese Journal of Applied Physics, Aug 1, 2022 Peer-reviewed
Evaluation of Damage Coefficient for Minority-Carrier Diffusion Length of Triple-Cation Perovskite Solar Cells under 1 MeV Electron Irradiation for Space Applications

Yu Miyazawa, Gyu Min Kim, Ayumi Ishii, Masashi Ikegami, Tsutomu Miyasaka, Yudai Suzuki, Tomoyuki Yamamoto, Takeshi Ohshima, Shusaku Kanaya, Hiroyuki Toyota, Kazuyuki Hirose

The Journal of Physical Chemistry C, 125(24) 13131-13137, Jun 24, 2021 Peer-reviewed
Solar power sail membrane prototype for OKEANOS mission

Masanori Matsushita, Toshihiro Chujo, Jun Matsumoto, Osamu Mori, Rikio Yokota, Hiroyuki Toyota, Yasutaka Satou, Nobukatsu Okuizumi, Hideki Kato, Tetsuya Nakamura, Yuichi Shibata, Tatsuro Nakao, Kazuyuki Mori, Sanae Fujii, Yuki Takao, Yuki Kubo, Yuya Miyamoto, Yuichiro Nada, Risa Motegi, Genki Ohira, Yudai Kimishima

Advances in Space Research, 67(9) 2899-2911, Oct, 2020 Peer-reviewedCorresponding author
Development of CubeSat Moon Lander OMOTENASHI

Tatsuaki Hashimoto, Junji Kikuchi, Ryo Hirasawa, Naoki Morishita, Nobutaka Bando, Atsushi Tomiki, Wataru Torii, Yuta Kobayashi, Shintaro Nakajima, Masatsugu Otsuki, Tetsuo Yoshimitsu, Tetsuya Yamada, Kota Miyoshi, Hiroyuki Toyota, Kakeru Tokunaga, Chikako Hirose, Toshinori Ikenaga, Aiko Nagamatsu, Hitoshi Morimoto

Proceedings of the International Astronautical Congress, IAC, 2020-October, 2020
Development and testing of the re-deployable radiator for deep space explorer

Yuki Akizuki, Hosei Nagano, Tomihiro Kinjo, Kenichiro Sawada, Hiroyuki Ogawa, Takeshi Takashima, Kazutaka Nishiyama, Hiroyuki Toyota, Kazuki Watanabe, Takeshi Kuratomi

Applied Thermal Engineering, 165 114586-114586, Jan, 2020 Peer-reviewedCorresponding author
Proton Irradiation Tolerance of High-Efficiency Perovskite Absorbers for Space Applications

Shusaku Kanaya, Gyu Min Kim, Masashi Ikegami, Tsutomu Miyasaka, Kohtaku Suzuki, Yu Miyazawa, Hiroyuki Toyota, Kanta Osonoe, Tomoyuki Yamamoto, Kazuyuki Hirose

The Journal of Physical Chemistry Letters, 10(22) 6990-6995, Nov 21, 2019 Peer-reviewedCorresponding author
Nano Semihard Moon Lander: OMOTENASHI

Tatsuaki Hashimoto, Tetsuya Yamada, Masatsugu Otsuki, Tetsuo Yoshimitsu, Atsushi Tomiki, Wataru Torii, Hiroyuki Toyota, Junji Kikuchi, Naoki Morishita, Yuta Kobayashi, Taichi Ito, Hideyuki Tanno, Aiko Nagamatsu, Hitoshi Morimoto

IEEE Aerospace and Electronic Systems Magazine, 34(9) 20-30, Sep 1, 2019 Peer-reviewedCorresponding author
Simulation and Ground Test for the Solar Array Using GaInP/GaAs/Ge Cells for Space Verification

Goo-Hwan Shin, Dong-Guk Kim, Se-Jin Kwon, Hu-Seung Lee, Hiroyuki Toyota

Journal of the Korean Physical Society, 74(11) 1079-1084, Jun, 2019 Peer-reviewedCorresponding author
Preliminary Study For Analyzing Planetary Atmosphere Using Solar Panel Output Current

Hiroyuki Toyota, Iku Shinohara

2019 EUROPEAN SPACE POWER CONFERENCE (ESPC), 2019
Exploration of energization and radiation in geospace (ERG): challenges, development, and operation of satellite systems

Yosuke Nakamura, Seisuke Fukuda, Yasuko Shibano, Hiroyuki Ogawa, Shin-ichiro Sakai, Shigehito Shimizu, Ersin Soken, Yu Miyazawa, Hiroyuki Toyota, Akio Kukita, Yusuke Maru, Junichi Nakatsuka, Tomohiko Sakai, Shinsuke Takeuchi, Kenichiro Maki, Makoto Mita, Emiko Ogawa, Yuya Kakehashi, Kumi Nitta, Kazushi Asamura, Takeshi Takashima, Iku Shinohara

Earth, Planets and Space, 70(1), Dec, 2018 Peer-reviewedCorresponding author
Characterization of stability of benchmark organic photovoltaic films after proton and electron bombardments

Jérémy Barbé, Harrison K. H. Lee, Hiroyuki Toyota, Kazuyuki Hirose, Shin-ichiro Sato, Takeshi Ohshima, Keith C. Heasman, Wing C. Tsoi

Applied Physics Letters, 113(18) 183301-183301, Oct 29, 2018 Peer-reviewedCorresponding author
DESTINY⁺: Technology demonstration and exploration of asteroid 3200 Phaethon

Kazutaka Nishiyama, Hiroyuki Toyota, Yasuhiro Kawakatsu, Tomoko Arai

Proceedings of the International Astronautical Congress, IAC, 5 2953-2958, 2017
AKATSUKI returns to Venus

Masato Nakamura, Takeshi Imamura, Nobuaki Ishii, Takumi Abe, Yasuhiro Kawakatsu, Chikako Hirose, Takehiko Satoh, Makoto Suzuki, Munetaka Ueno, Atsushi Yamazaki, Naomoto Iwagami, Shigeto Watanabe, Makoto Taguchi, Tetsuya Fukuhara, Yukihiro Takahashi, Manabu Yamada, Masataka Imai, Shoko Ohtsuki, Kazunori Uemizu, George L. Hashimoto, Masahiro Takagi, Yoshihisa Matsuda, Kazunori Ogohara, Naoki Sato, Yasumasa Kasaba, Toru Kouyama, Naru Hirata, Ryosuke Nakamura, Yukio Yamamoto, Takeshi Horinouchi, Masaru Yamamoto, Yoshi-Yuki Hayashi, Hiroki Kashimura, Ko-ichiro Sugiyama, Takeshi Sakanoi, Hiroki Ando, Shin-ya Murakami, Takao M. Sato, Seiko Takagi, Kensuke Nakajima, Javier Peralta, Yeon Joo Lee, Junichi Nakatsuka, Tsutomu Ichikawa, Kozaburo Inoue, Tomoaki Toda, Hiroyuki Toyota, Sumitaka Tachikawa, Shinichiro Narita, Tomoko Hayashiyama, Akiko Hasegawa, Yukio Kamata

Earth, Planets and Space, 68(1), Dec, 2016 Peer-reviewedCorresponding author
Polarized photoluminescence imaging analysis around small-angle grain boundaries in multicrystalline silicon wafers for solar cells

Gen Kato, Michio Tajima, Hiroyuki Toyota, Atsushi Ogura

Japanese Journal of Applied Physics, 53(8) 080303-080303, Aug 1, 2014 Peer-reviewedCorresponding author

We have shown the effectiveness of polarized photoluminescence imaging for analyzing the structural and spectroscopic properties of small-angle grain boundaries (SA-GBs) in multicrystalline Si. The dislocation-related deep-level emission band at approximately 0.79 eV at room temperature was found to be polarized, whereas the band-edge emission did not show the polarization effect. The anisotropy of the 0.79 eV band was classified into two groups depending on the tilt and twist characteristics of SA-GBs determined by the electron backscatter diffraction measurement.
Photoluminescence Analysis of Oxygen Precipitation around Small-Angle Grain Boundaries in Multicrystalline Silicon Wafers

G. Kato, M. Tajima, F. Okayama, S. Tokumaru, R. Sato, H. Toyota, A. Ogura

Acta Physica Polonica A, 125(4) 1010-1012, Apr, 2014
On-orbit Performance Analysis on Solar Array Paddle of X-ray Astronomy Satellite "Suzaku"

Takanobu Shimada, Hiroyuki Toyota, Kazuyuki Hirose, Yoshitomo Maeda, Kazuhisa Mitsuda

2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC), 2161-2165, 2014
Donor-acceptor pair luminescence in B and P compensated Si co-doped with Ga

Michio Tajima, Koji Tanaka, Maxime Forster, Hiroyuki Toyota, Atsushi Ogura

Journal of Applied Physics, 113(24) 243701-243701, Jun 28, 2013 Peer-reviewedCorresponding author
Thermal Design for High-Temperature High-Irradiance Testing of Space Solar Panel Components

Philip Blumenfeld, Andreea Boca, Paul Sharps, Dennis Russell, Hiroyuki Ogawa, Hiroyuki Toyota

2013 IEEE 39TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC), 647-651, 2013
Deep-level photoluminescence due to dislocations and oxygen precipitates in multicrystalline Si

Michio Tajima, Yasuaki Iwata, Futoshi Okayama, Hiroyuki Toyota, Hisashi Onodera, Takashi Sekiguchi

Journal of Applied Physics, 111(11) 113523-113523, Jun, 2012 Peer-reviewedCorresponding author
High-speed deep-level luminescence imaging in multicrystalline Si solar cells

Futoshi Okayama, Michio Tajima, Hiroyuki Toyota, Atsushi Ogura

Materials Science Forum, 725 149-152, 2012
Donor−acceptor pair luminescence in compensated Si for solar cells

Michio Tajima, Takaaki Iwai, Hiroyuki Toyota, Simona Binetti, Daniel Macdonald

Journal of Applied Physics, 110(4) 043506-043506, Aug 15, 2011 Peer-reviewedCorresponding author
Fine Structure Due to Donor–Acceptor Pair Luminescence in Compensated Si

Michio Tajima, Takaaki Iwai, Hiroyuki Toyota, Simona Binetti, Daniel Macdonald

Applied Physics Express, 3(7) 071301-071301, Jun 18, 2010 Peer-reviewedCorresponding author

A fine structure on the higher energy side of donor--acceptor (DA) pair luminescence at 4.2 K has been analyzed in compensated Si involving P donors and B acceptors. We calculated the density distribution of DA pairs against photon energy from the number of pairs as a function of the transition energy of respective pairs. A close agreement was obtained between the density curve and the observed spectral structure using the generally accepted values of energy gap and P donor and B acceptor ionization energies. This allows us to conclude that the structure is due to discrete DA pair recombination.
Durability evaluation of InGaP/GaAs/Ge triple-junction solar cells in HIHT environments for Mercury exploration mission

T. Shimada, H. Toyota, A. Kukita, M. Imaizumi, K. Hirose, M. Tajima, H. Ogawa, H. Hayakawa, A. Okamoto, Y. Nozaki, H. Watabe, T. Hisamatsu

Conference Record of the IEEE Photovoltaic Specialists Conference, 1112-1117, 2010 Peer-reviewed
Energy storage system based on supercapacitors with an unregulated dc-dc converter and selective intermediate taps

Masatoshi Uno, Hiroyuki Toyota

2008 IEEE International Conference on Sustainable Energy Technologies, Nov, 2008
Equalization technique utilizing series-parallel connected supercapacitors for energy storage system

Masatoshi Uno, Hiroyuki Toyota

2008 IEEE International Conference on Sustainable Energy Technologies, Nov, 2008
Supercapacitor-based energy storage system with voltage equalizers and selective taps

Masatoshi Uno, Hiroyuki Toyota

2008 IEEE Power Electronics Specialists Conference, Jun, 2008
Durability of triple-junction solar cell for HIHT environments, Venus and Mercury exploration missions

M. Imaizumi, H. Toyota, T. Shimada, H. Ogawa, M. Tajima, T. Hisamatsu, K. Nakamura, T. Takamoto, S. Satoh, T. Ohshima

European Space Agency, (Special Publication) ESA SP, (661), 2008
Development of lithium-ion battery for the Venus climate orbiter "PLANET-C"

Hiroki Ooto, Kenji Ohira, Masahiro Yamamoto, Takashi Eguro, Hiroyuki Toyota, Masatoshi Uno, Kazuyuki Hirose, Michio Tajima

European Space Agency, (Special Publication) ESA SP, (661), 2008
Venus climate orbiter PLANET-C solar array development

H. Toyota, T. Shimada, K. Higuchi, M. Uno, K. Hirose, M. Tajima, N. Ishii, M. Imaizumi, Y. Nozaki, N. Kaneko, M. Konno

European Space Agency, (Special Publication) ESA SP, (661), 2008
Basic Experiment of Plasma Interaction with High Voltage Solar Array

Koji Tanaka, Hiroyuki Toyota, Michio Tajima, Susumu Sasaki, Sachiko Katagiri

45th AIAA Aerospace Sciences Meeting and Exhibit, Jan 8, 2007

Misc.

宇宙用電池の技術変遷と将来展望

豊田裕之

FBテクニカルニュース, 81(2)-19, Dec, 2025 Invited
The Design of CubeSat Moon Lander OMOTENASHI

HASHIMOTO Tatsuaki, KIKUCHI Junji, HIROSE Chikako, OTSUKI Masatsugu, HIRASAWA Ryo, TOYOTA Hiroyuki, MIYOSHI Kota, YOSHIMITSU Tetsuo, ISHIGE Yasuo, TORII Wataru, TOMIKI Atsushi, BANDO Nobutaka, MORISHITA Naoki, NAGAMATSU Aiko, TOKUNAGA Kakeru, HORI Keiichi, ITO Taichi, NAKAJIMA Shintaro

JAXA Research and Development Report, JAXA-RR-24-003 1-134, Feb, 2025 Peer-reviewed
深宇宙探査技術実証機DESTINY+プロジェクトの進捗

荒井朋子, 小林正規, 石橋高, 木村宏, 奥平修, 山田学, 岡本尚也, 吉田二美, 吉田二美, 和田浩二, 千秋博紀, 秋田谷洋, SRAMA Ralf, KRUGER Harald, KRUGER Harald, 諸田智克, 佐々木晶, 石黒正晃, 関口朋彦, 大塚勝仁, 大塚勝仁, 浦川聖太郎, 阿部新助, 巽瑛理, 横田康弘, 薮田ひかる, 渡部潤一, 伊藤孝士, 伊藤孝士, 大坪貴文, 大坪貴文, 中村智樹, 廣井孝弘, 平田成, 小松吾郎, 小松吾郎, 紅山仁, 伊藤元雄, 山口亮, 松浦周二, MARSHALL Sean, 矢野創, 吉川真, 尾崎直哉, 山本高行, 豊田裕之, 西山和孝, 今村裕志, 高島建

日本惑星科学会秋季講演会予稿集(Web), 2025, 2025
太陽の子・塵の母「Phaethon」をフライバイ!(その1)深宇宙探査技術実証機デスティニー・プラスDESTINY PLUSの計画概要とサイエンス

荒井朋子, 小林正規, 石橋高, 吉田二美, 木村宏, 平井隆之, 岡本尚也, 洪鵬, 山田学, 和田浩二, 千秋博紀, 秋田谷洋, Ralf Srama, Harald Kruger, Sean Marshall, 佐々木晶, 薮田ひかる, 石黒正晃, 中村智樹, 大塚勝仁, 渡部潤一, 伊藤孝士, 大坪貴文, 阿部新助, 関口朋彦, 浦川聖太郎, 廣井孝弘, 紅山仁, 諸田智克, 橘省吾, 三河内岳, 松浦周二, 伊藤元雄, 山口亮, 野口高明, 中村メッセンジャー圭子, 小松睦美, 小松吾郎, 出村裕英, 平田成, 金田英宏, 柳沢俊史, 黒崎裕久, 巽瑛理, 矢野創, 吉川真, 尾崎直哉, 山本高行, 餅原義孝, 徳留真一郎, 豊田裕之, 西山和孝, 今村裕志, 高島建

遊・星・人 = Planetary people : 日本惑星科学会誌, 33(1) 34-50, Mar, 2024
Mission Design of DESTINY⁺

山本高行, 尾崎直哉, 秋山祐貴, 西山和孝, 豊田裕之, 今村裕志, 高島健, 近澤拓弥

宇宙科学技術連合講演会講演集(CD-ROM), 67th, 2023

Presentations

InGaP系多接合太陽電池が実現したJAXA宇宙科学ミッションの軌跡と進化

豊田裕之

豊田工業大学山口眞史名誉教授紫綬褒章受章記念講演会, Jun 26, 2025 Invited
Development of Lightweight Solar Array Panel for Japan’s Lunar Lander SLIM

Toyota, H., Kanaya, S., Miyazawa, Y., Kukita, A., Nakamura, T., Sumita, T., Fukuda, S., Sawai, S., Sakai, S., Yamaguchi, H., Juso, H., Washio, H., Takamoto, T.

35th International Photovoltaic Science and Engineering Conference, Nov, 2024 Invited
太陽電池が牽引する宇宙科学ミッション～はやぶさ、SLIM、その先へ～

豊田裕之

日本太陽光発電学会次世代太陽電池セル・モジュール分科会 2023年度第2回研究会, Mar 1, 2024 Invited
宇宙機搭載電源システムの概要と宇宙用太陽電池の最新動向

豊田裕之

宇宙工学講座「宇宙機搭載電源の入門講座」, Oct 25, 2023 Invited
Effects of Radiation on Solar Arrays

Hiroyuki Toyota

2023 Satellite Science Workshop, Jun 16, 2023 Invited

Teaching Experience

Apr, 2016 - Present

High-voltage engineering (Meisei University)

Research Projects

Key technology Research and High-altitude demonstration to realize the world first Mars exploration using Airplane

Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2012 - Mar, 2015

NAGAI Hiroki, OYAMA Akira, TOKUTAKE Hiroshi, TAKEUCHI Shinsuke, TOYOTA Hiroyuki, OTSUKI Masatsugu, NONOMURA Taku, ANYOJI Masayuki, YONEMOTO Koichi, FUJII Kozo, ASAI Keisuke

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