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Okuno, Yasuki*; Ishikawa, Norito; Akiyoshi, Masafumi*; Ando, Hirokazu*; Harumoto, Masaki*; Imaizumi, Mitsuru*
Japanese Journal of Applied Physics, 59(7), p.074001_1 - 074001_7, 2020/07
Times Cited Count：3 Percentile：19.49(Physics, Applied)Performance degradation prediction for space solar cells under irradiation with low-energy electrons is greatly affected by displacement threshold energy (Ed) when a displacement damage dose (DDD) model is used. According to recent studies, the Ed of P atoms is much lower than the conventional Ed value in InP-type solar cells irradiated with low-energy electrons. This indicates that the value of Ed typically used in DDD model leads to significant error in performance degradation prediction. In this study, degradation of AlInGaP solar cells is observed after irradiation with 60 keV electrons. The results suggest that the Ed of P atoms in AlInGaP solar cells is much smaller than the conventionally used Ed value. By using the DDD model with the Ed value obtained in this study, we demonstrated that the performance degradation predicted by the DDD model agrees well with the experimental results.
Sekiguchi, Tetsuhiro; Baba, Yuji; Hirao, Norie; Honda, Mitsunori; Izumi, Toshinori; Ikeura, Hiromi*
Molecular Crystals and Liquid Crystals, 622(1), p.44 - 49, 2015/12
Times Cited Count：0 Percentile：0.01(Chemistry, Multidisciplinary)The molecular orientation is one of the important factors for controlling various properties in organic semiconductor materials. Films are usually heterogeneous. Thus they exist as a mixture of microscopic domains which have a variety of orientation directions. Therefore, it is essential to observe selectively microscopic domains with different orientation direction. In this work, we have developed the photoelectron emission microscopy (PEEM) system combined with the linearly polarized vacuum ultraviolet (VUV) light or synchrotron radiation (SR) X-rays. PEEM images (FOV = ca.50 micro m) for poly(3-hexylthiophene), P3HT thin films were observed under the UV irradiation with various polarization angles, including in-plain and out-of-plain polarization. Morphologies at some bright parts are different each other. The resultant observation suggests that it enables us to distinguish oriented micro-domains with specific directions of polymer chain axis from other amorphous parts.
Shibata, Yuichi*; Imaizumi, Mitsuru*; Sato, Shinichiro; Oshima, Takeshi; Ooka, Sachiyo*; Takamoto, Tatsuya*
Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.65 - 68, 2015/11
Radiation response is one of the important properties for space solar cells. It should be well understood so as to accurately predict their degradation in orbit and also to improve their radiation tolerance. Recently, a phenomenon, recovery from the radiation degradation by light soaking, on inverted metamorphic (IMM) triple-junction (3J) solar cells was found out. In this work, the light soaking annealing effects on electron irradiated IMM 3J solar cells are reported. IMM 3J solar cells irradiated with 1 MeV electrons with the fluence of 3
10
e
/cm
showed the recovery of open-circuit voltage, Voc, up to 43 mV after light (AM0, 1 sun) soaking of 3 hours. The increment of the electroluminescence intensity for InGaP in the IMM 3J cells due to the light soaking suggests that the Voc recovery occurs in InGaP top-cell rather than GaAs middle-cell or InGaAs bottom-cell.
Nakamura, Tetsuya*; Imaizumi, Mitsuru*; Sato, Shinichiro; Sugaya, Takeyoshi*; Mochizuki, Toru*; Okano, Yoshinobu*; Oshima, Takeshi
Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.73 - 76, 2015/11
The radiation effect on GaAs p-i-n solar cells with quantum dot (QD) in the i-layer was investigated. In a previous work, we particularly noted the degradation of fill-factor (FF) for the QD cells. In this work, to clarify the reason of the FF degradation in QD cells, generation current due to low-energy proton irradiation, which we call ion beam induced current (IBIC), was observed to characterize behavior of the generated minority carrier by the protons in the depletion region where QDs are located. The energy of protons was adjusted to damage the depletion region, and decrease of generation current was measured during the proton irradiation. The results suggest that the serious degradation of FF is caused by a decrease of the carrier collection efficiency in the depletion region due to proton damage.
Sato, Shinichiro; Beernink, K.*; Oshima, Takeshi
Japanese Journal of Applied Physics, 54(6), p.061401_1 - 061401_6, 2015/06
Times Cited Count：5 Percentile：22.94(Physics, Applied)Performance degradation and immediate recovery of a-Si/a-SiGe/a-SiGe triple-junction solar cells due to irradiation of silicon ions, electrons, and protons are investigated. Significant recovery is always observed independent of radiation species and temperature. It is shown that the characteristic time, which is obtained by analyzing the short-circuit current annealing behavior, is an important parameter for practical applications in space. In addition, the radiation degradation mechanism is discussed by analyzing the energy loss process of incident particles (ionizing energy loss: IEL, and non-ionizing energy loss: NIEL) and their relative damage factors. It is determined that ionizing dose is the primarily parameter for electron degradation whereas displacement damage dose is the primarily parameter for proton degradation. The impact of "radiation quality effect" has to be considered to understand the degradation due to Si ion irradiation.
Miyazawa, Yu*; Ikegami, Masashi*; Miyasaka, Tsutomu*; Oshima, Takeshi; Imaizumi, Mitsuru*; Hirose, Kazuyuki*
Proceedings of 42nd IEEE Photovoltaic Specialists Conference (PVSC-42) (CD-ROM), p.1178 - 1181, 2015/06
Shimazaki, Kazunori*; Kobayashi, Yuki*; Takahashi, Masato*; Imaizumi, Mitsuru*; Murashima, Mio*; Takahashi, Yu*; Toyota, Hiroyuki*; Kukita, Akio*; Oshima, Takeshi; Sato, Shinichiro; et al.
Proceedings of 40th IEEE Photovoltaic Specialists Conference (PVSC-40) (CD-ROM), p.2149 - 2154, 2014/06
The electrical performance of a glass-type space solar sheet (G-SSS) was demonstrated in space. G-SSS comprises InGaP/GaAs dual-junction and InGaP/GaAs/InGaAs triplejunction solar cells. It is lightweight solar generation sheet, less than 0.5 mm thick. It is mounted on the "HISAKI" (SPRINT-A) small scientific satellite, which was launched on September 14, 2013. The initial flight data were successfully acquired and this flight demonstration was a world-first experiment for G-SSS using III-V multi-junction thin-film solar cells. The cells demonstrated superior performance and the electrical outputs matched the flight prediction.
Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Hirao, Norie; Honda, Mitsunori; Izumi, Toshinori; Ikeura, Hiromi*
Photon Factory Activity Report 2013, Part B, P. 546, 2014/00
The molecular orientation is one of the important factors for controlling various properties in organic semiconductor materials. Films are usually heterogeneous. Thus they exist as a mixture of microscopic domains which have a variety of orientation directions. Therefore, it is essential to observe selectively microscopic domains with different orientation direction. In this work, we have developed the photoelectron emission microscope (PEEM) system combined with the linearly polarized vacuum ultraviolet (VUV) light or synchrotron radiation (SR) X-rays. PEEM images for poly(3-hexylthiophene), P3HT thin films were observed under synchrotron X-ray irradiation with linearly polarization. In conclusion, it was found that PEEM with polarized synchrotron can be a powerful tool that gives information of molecular orientation in nano-meter scale.
Yamaguchi, Kenji; Udono, Haruhiko*
International Journal of Hydrogen Energy, 32(14), p.2726 - 2729, 2007/09
Times Cited Count：14 Percentile：36.77(Chemistry, Physical)no abstracts in English
/p-AlInGaP solar cellsLee, H. S.*; Yamaguchi, Masafumi*; Ekins-Daukes, N. J.*; Khan, A.*; Takamoto, Tatsuya*; Imaizumi, Mitsuru*; Oshima, Takeshi; Ito, Hisayoshi
Physica B; Condensed Matter, 376-377, p.564 - 567, 2006/04
Times Cited Count：2 Percentile：12.58(Physics, Condensed Matter)no abstracts in English
Oshima, Takeshi; Sumita, Taishi*; Imaizumi, Mitsuru*; Kawakita, Shiro*; Shimazaki, Kazunori*; Kuwajima, Saburo*; Oi, Akihiko*; Ito, Hisayoshi
Proceedings of 31st IEEE Photovoltaic Specialists Conference and Exhibition (PVSC-31), p.806 - 809, 2005/00
no abstracts in English
Sumita, Taishi*; Imaizumi, Mitsuru*; Oshima, Takeshi; Ito, Hisayoshi; Kuwajima, Saburo*
Proceedings of 31st IEEE Photovoltaic Specialists Conference and Exhibition (PVSC-31), p.667 - 670, 2005/00
no abstracts in English
Imaizumi, Mitsuru*; Sumita, Taishi*; Kawakita, Shiro*; Oshima, Takeshi; Ito, Hisayoshi; Kuwajima, Saburo*
Proceedings of 31st IEEE Photovoltaic Specialists Conference and Exhibition (PVSC-31), p.563 - 566, 2005/00
no abstracts in English
Lee, H. S.*; Ekins-Daukes, N. J.*; Sasaki, Takuo*; Yamaguchi, Masafumi*; Khan, A.*; Takamoto, Tatsuya*; Agui, Takaaki*; Kamimura, Kunio*; Kaneiwa, Minoru*; Imaizumi, Mitsuru*; et al.
Proceedings of 31st IEEE Photovoltaic Specialists Conference and Exhibition (PVSC-31), p.556 - 558, 2005/00
no abstracts in English
Ekins-Daukes, N. J.*; Arafune, Koji*; Lee, H. S.*; Sasaki, Takuo*; Yamaguchi, Masafumi*; Khan, A.*; Takamoto, Tatsuya*; Agui, Takaaki*; Kamimura, Kunio*; Kaneiwa, Minoru*; et al.
Proceedings of 31st IEEE Photovoltaic Specialists Conference and Exhibition (PVSC-31), p.683 - 686, 2005/00
no abstracts in English
Chandrasekaran, N.*; Soga, Tetsuo*; Inuzuka, Yosuke*; Taguchi, Hironori*; Imaizumi, Mitsuru*; Oshima, Takeshi; Jimbo, Takashi*
Japanese Journal of Applied Physics, 43(10A), p.L1302 - L1304, 2004/10
Times Cited Count：6 Percentile：27.83(Physics, Applied)no abstracts in English
thin-film solar cells for space useKawakita, Shiro*; Shimazaki, Kazunori*; Imaizumi, Mitsuru*; Kuwajima, Saburo*; Yoda, Shinichi*; Oshima, Takeshi; Ito, Hisayoshi
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.151 - 154, 2004/10
no abstracts in English
filmsOkada, Hiroshi*; Natsume, Satoshi*; Wakahara, Akihiro*; Yoshida, Akira*; Oshima, Takeshi; Kamiya, Tomihiro
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.147 - 150, 2004/10
no abstracts in English
Ekins-Daukes, N. J.*; Lee, H. S.*; Sasaki, Takuo*; Yamaguchi, Masafumi*; Khan, A.*; Takamoto, Tatsuya*; Agui, Takaaki*; Kamimura, Kunio*; Kaneiwa, Minoru*; Imaizumi, Mitsuru*; et al.
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.87 - 91, 2004/10
no abstracts in English
Ekins-Daukes, N. J.*; Lee, H. S.*; Sasaki, Takuo*; Yamaguchi, Masafumi*; Khan, A.*; Takamoto, Tatsuya*; Agui, Takaaki*; Kamimura, Kunio*; Kaneiwa, Minoru*; Imaizumi, Mitsuru*; et al.
Applied Physics Letters, 85(13), p.2511 - 2513, 2004/09
Times Cited Count：11 Percentile：42.77(Physics, Applied)no abstracts in English
