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Shindo, Hiroyuki*; Kuboyama, Satoshi*; Ikeda, Naomi*; Otomo, Hiromitsu*; Shimada, Osamu*; Hirao, Toshio; Matsuda, Sumio*
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.63 - 66, 2004/10
no abstracts in English
Kuboyama, Satoshi*; Ikeda, Naomi*; Hirao, Toshio; Matsuda, Sumio*
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.165 - 168, 2004/10
no abstracts in English
Oyama, Hidenori*; Takakura, Kenichiro*; Nakabayashi, Masakazu*; Hirao, Toshio; Onoda, Shinobu; Kamiya, Tomihiro; Simoen, E.*; Claeys, C.*; Kuboyama, Satoshi*; Oka, Katsumi*; et al.
Nuclear Instruments and Methods in Physics Research B, 219-220, p.718 - 721, 2004/06
Times Cited Count：3 Percentile：24.89(Instruments & Instrumentation)no abstracts in English
Imaizumi, Mitsuru*; Takamoto, Tatsuya*; Sumita, Taishi*; Oshima, Takeshi; Yamaguchi, Masafumi*; Matsuda, Sumio*; Oi, Akihiko; Kamiya, Tomihiro
Proceedings of 3rd World Conference on Photovoltaic Energy Conversion (WCPEC-3) (CD-ROM), 4 Pages, 2004/01
The radiation response of InGaP, InGaAs and Ge single junction sub-cells in the triple junction space solar cell are studied in order to develop a device simulator which predicts the End-Of-Life performance of space solar cells. InGaP top-cells show no significant difference in radiation response between under AM0 light and dark conditions during irradiation. The radiation resistance of InGaAs cell which is used as middle cell decreases with increasing In contents. The Ge cell shows lower radiation reisitance as compared to InGaP and InGaAs cells.
Kawakita, Shiro*; Imaizumi, Mitsuru*; Sumita, Taishi*; Kushiya, Katsumi*; Oshima, Takeshi; Yamaguchi, Masafumi*; Matsuda, Sumio*; Yoda, Shinichi*; Kamiya, Tomihiro
Proceedings of 3rd World Conference on Photovoltaic Energy Conversion (WCPEC-3) (CD-ROM), 4 Pages, 2004/01
The electrical performance of Cu(Ga,In)Se
solar cells on MDS-1 which was launched in February 2002 was measured. The CIGS solar cells show superior radiation resistance in space. The short circuit current dose not degrade and the open circuit voltage shows only 1 % degradation after 200 days. On the other hand, in the case of ground test, the recovery of electrical performance of CIGS solar cells are observed at RT. And, the recovery is enhanced by current-injection.
Sumita, Taishi*; Imaizumi, Mitsuru*; Matsuda, Sumio*; Oshima, Takeshi; Oi, Akihiko; Kamiya, Tomihiro
Proceedings of 3rd World Conference on Photovoltaic Energy Conversion (WCPEC-3) (CD-ROM), 4 Pages, 2004/01
While high beginning-of-life efficiencies are important for space solar cells, the end-of-life performance is also critical factor. Two different prediction methods, "relative damage dose" and "displacement damage dose" methods, based on analysis of ground radiation test have been produced. We report proton radiation response for triple-junction space solar cells and analyze prediction methodology for the cell radiation response using the two methods. The results show that V
degradation behavior can be predicted by taking into account a cell structure and proton penetration depth. Accurate prediction of power degradation, however, is required to determine the current-limiting sub cell after proton irradiations.
Shindo, Hiroyuki*; Kuboyama, Satoshi*; Ikeda, Naomi*; Hirao, Toshio; Matsuda, Sumio*
IEEE Transactions on Nuclear Science, 50(6, Part1), p.1839 - 1845, 2003/12
Times Cited Count：17 Percentile：72.74(Engineering, Electrical & Electronic)no abstracts in English
thin filmsLee, H.-S.*; Okada, Hiroshi*; Wakahara, Akihiro*; Yoshida, Akira*; Oshima, Takeshi; Ito, Hisayoshi; Kawakita, Shiro*; Imaizumi, Mitsuru*; Matsuda, Sumio*
Physica Status Solidi (A), 199(3), p.471 - 474, 2003/10
Times Cited Count：3 Percentile：21.33(Materials Science, Multidisciplinary)no abstracts in English
thin filmsLee, H.-S.*; Okada, Hiroshi*; Wakahara, Akihiro*; Oshima, Takeshi; Ito, Hisayoshi; Kawakita, Shiro*; Imaizumi, Mitsuru*; Matsuda, Sumio*; Yoshida, Akira*
Journal of Physics and Chemistry of Solids, 64(9-10), p.1887 - 1890, 2003/09
Times Cited Count：12 Percentile：53.9(Chemistry, Multidisciplinary)no abstracts in English
Sumita, Taishi*; Imaizumi, Mitsuru*; Matsuda, Sumio*; Oshima, Takeshi; Oi, Akihiko; Ito, Hisayoshi
Nuclear Instruments and Methods in Physics Research B, 206, p.448 - 451, 2003/05
Times Cited Count：54 Percentile：94.59(Instruments & Instrumentation)Proton irradiation effects of triple-junction (InGaP/GaAs/Ge) solar cells for space use were studied. The changes in electrical and optical properties of the solar cells irradiated with protons at energies between 20 keV and 10 MeV were examined. As the result of analyzing the relationship between proton projection range and the degradation of their properties, the largest degradation of the properties was observed when proton projection range is near the junction of GaAs sub-cells. This indicates that improvement of the radiation resistance of GaAs is necessary to enhance radiation resistance of tliple-junction solar cells.
/p InGaP solar cellDharmarasu, N.*; Yamaguchi, Masafumi*; Khan, A.*; Takamoto, Tatsuya*; Oshima, Takeshi; Ito, Hisayoshi; Imaizumi, Mitsuru*; Matsuda, Sumio*
Solar Energy Materials and Solar Cells, 75(1-2), p.327 - 333, 2003/01
Times Cited Count：3 Percentile：30.01(Energy & Fuels)n/p InGaP junctions were irradiated with 100keV-protons, and the effect on their electrical properties were studied using C-V and DLTS methods.The n/p InGaP junctions were fabricated by MOCVD method.They were irradiated up to 1E12 /cm
at RT. The carrier removal rate was estimated to be 6.1E4 cm
from the fluence dependence of carrier concentration. H1 peaks which were observed at 400 K in DLTS measurements were found after irradiation.It was concluded that H1 peaks relates residual defects which act as carrier removal centers.
Kuboyama, Satoshi*; Shindo, Hiroyuki*; Hirao, Toshio; Matsuda, Sumio*
IEEE Transactions on Nuclear Science, 49(6), p.2684 - 2689, 2002/12
Times Cited Count：10 Percentile：54.86(Engineering, Electrical & Electronic)no abstracts in English
Oshima, Takeshi; Imaizumi, Mitsuru*; Takamoto, Tatsuya*; Sumita, Taishi*; Oi, Akihiko; Kawakita, Shiro*; Ito, Hisayoshi; Matsuda, Sumio*
Proceedings of 5th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications, p.113 - 116, 2002/10
The effects on proton and electron irradiateions of the characteristics of InGaP/GaAs/Ge triple junction designed for terrestrial application were studied. The solar cells used in this study has a 1% In-contained GaAs middle sub-cell, and their efficiency is more than 30 % under AM1.5, which is the highest efficiency of all solar cells in the world.As the results of 1MeV-electron and 10 MeV-proton irradiation, terrestrial triple-junction sole cells were found to have the same radiation resistance as space single junction GaAs solar cells, although terrestrial triple-junction solar cells is not stronger than space triple-junction solar cells made in USA. As the result of proton energy dependence of the electrical characteristics and quantum efficiency, the strong degradation of the GaAs middle cell was observed.
-InGaP space solar cellsDharmarasu, N.*; Yamaguchi, Masafumi*; Bourgoin, J. C.*; Takamoto, Tatsuya*; Oshima, Takeshi; Ito, Hisayoshi; Imaizumi, Mitsuru*; Matsuda, Sumio*
Applied Physics Letters, 81(1), p.64 - 66, 2002/07
Times Cited Count：17 Percentile：55.85(Physics, Applied)We studied the properties of observed defects in n/p-InGaP solar cells created by irradiation of protons with different energies.Three majority (hole) and a minority-carrier traps, labeled respectively as HP1 (E
+0.90
0.05eV), HP2 (E+0.730.05eV), H2 (E +0.55eV),and EP1 (E
0.54eV),were identified using deep level transient spectroscopy. All majority-carrier traps were found to act as recombination centers. While the H2 traps present in the proton-irradiated p-InGaP was found to anneal out by minority-carrier injection, the other traps were not.
thin-film solar cellsKawakita, Shiro*; Imaizumi, Mitsuru*; Yamaguchi, Masafumi*; Kushiya, Katsumi*; Oshima, Takeshi; Ito, Hisayoshi; Matsuda, Sumio*
Japanese Journal of Applied Physics, Part 2, 41(7A), p.L797 - L799, 2002/07
Recovery of electrical characteristics of Cu(In,Ga)Se irradiated with protons was studied. A proton irradiation chamber which has a AM0 solar light was used for in-situ measurement in this study. The electrical characteristics of irradiated samples which were kept under a dark condition recovered. Furthermore,this recovery effect was enhanced by light illumination. The activation energy for the recovery was estimated to be 0.80 eV (light illumination case) and 0.92 eV (dark condition case).
InGaP solar CellsDharmarasu, N.*; Khan, A.*; Yamaguchi, Masafumi*; Takamoto, Tatsuya*; Oshima, Takeshi; Ito, Hisayoshi; Imaizumi, Mitsuru*; Matsuda, Sumio*
Journal of Applied Physics, 91(5), p.3306 - 3311, 2002/03
Times Cited Count：25 Percentile：66.97(Physics, Applied)3MeV proton irradiation effects on InGaP single junction and InGaP/GaAs two junction cells were studied. The degradation of electrocal properties for InGaP cells was smaller than that for InGaP/GaAs cells. The results of the measurement of spectral response showed the large degradation in long wavelength. This indicates that GaAs cell degrades. The Damage coefficient of minority carrier diffusion length was estimated to be 7.9
10
for InGaP and 1.610
for GaAs. These values of the damage coefficient for InGaP and GaAs are 580 times and 280 times larger than those for InGaP and GaAs irradiated with 1MeV electrons.
Hirao, Toshio; Shindo, Hiroyuki*; Kuboyama, Satoshi*; Nagai, Yuki*; Ohira, Hideharu*; Ito, Hisayoshi; Matsuda, Sumio*
JNC TN7200 2001-001, p.66 - 68, 2002/01
no abstracts in English
/p InGaP solar cellDharmarasu, N.*; Yamaguchi, Masafumi*; Khan, K.*; Takamoto, Tatsuya*; Oshima, Takeshi; Ito, Hisayoshi; Imaizumi, Mitsuru*; Matsuda, Sumio*
Physica B; Condensed Matter, 308-310, p.1181 - 1184, 2001/12
Times Cited Count：7 Percentile：41.38(Physics, Condensed Matter)Carrier concentration and defects in n+/p InGaP irradiated with 100keV-protons (1E10, 5E12 /cm2) were studied.As a result of C-V measurements, the carrier removal rate was estimated to be 6.1E4 /cm2 which was extremely high as compared to 1MeV-electron irradiation case (0.93 /cm). H1 peak whose energy corresponds to Ev+0.90V was obtained from DLTS measurements. This suggests that carrier removal rate in proton-irradiated ones is much higher than that in electron-irradiated ones due to the generation of the defects (H1 peak) which act as majority carrier traps.
Dharmarasu, N.*; Yamaguchi, Masafumi*; Khan, A.*; Yamada, Takashi*; Tanabe, Tatsuya*; Takagishi, Shigenori*; Takamoto, Tatsuya*; Oshima, Takeshi; Ito, Hisayoshi; Imaizumi, Mitsuru*; et al.
Applied Physics Letters, 79(15), p.2399 - 2401, 2001/10
Times Cited Count：75 Percentile：90.93(Physics, Applied)The radiation response of 3MeV proton-irradiated InGaP, InGaAsP, and InGaAs solar cells was measured and analyzed in comparison with those of InP and GaAs. The degradation of the minority-carrier diffusion length was estimated from the spectral response. The damage coefficient K
for 3MeV proton-irradiated InGaP, InGaAsP and InGaAs was also determined. The radiation resistance increases with increase in the function of In-P bonds in those materials. Minority-carrier injection under forward bias is found to cause partial recovery of the degradation on irradiated InGaP and InGaAsP cells.
Khan, A.*; Yamaguchi, Masafumi*; Oshita, Yoshio*; Dharmarasu, N.*; Araki, Kenji*; Abe, Takao*; Ito, Hisayoshi; Oshima, Takeshi; Imaizumi, Mitsuru*; Matsuda, Sumio*
Journal of Applied Physics, 90(3), p.1170 - 1178, 2001/08
Times Cited Count：56 Percentile：86.43(Physics, Applied)1MeV-electron and 10MeV-proton irradiations into Si doped various impurities such as B, Ga, O and C were performed and residual defects in the Si were studied using DLTS and C-V measurements.It was revealed that Ci-Oi whose level is Ev-0.36 eV and Bi-Oi whose energy is Ec-0.18eV were generated. In Ga-doped Si, the generation of Ci-Oi was suppressed. Since Ci-Oi acts as scattering center, this result indicates that the radiation resistance of solar cells is improved by using Ga-doped Si substrates.Furthermore, a new defect level (Ev+18eV) was observed in Ga-dpoed Si by irradiation. This defect level was annealed out above 350 C.
