@inproceedings{oai:jaxa.repo.nii.ac.jp:00008091, author = {杉本, 広紀 and 田島, 道夫 and 今泉, 充 and Sugimoto, Hiroki and Tajima, Michio and Imaizumi, Mitsuru}, book = {第24回宇宙エネルギーシンポジウム 平成16年度, The Twenty-fourth Space Energy Symposium March 7, 2005}, month = {Jun}, note = {Multijunction (MJ) solar cells have received extensive attention for use in space satellites because of their high efficiency. The radiation tolerance of the cells is important for space applications. Understanding the degradation mechanisms is essential to develop high quality MJ cells, although investigation of the radiation effects in these cells is very difficult because of their complex structure. The purposes of this study were to develop useful methods with which to evaluate radiation effects in the respective sub cells of the MJ cell, and to investigate their degradation mechanisms. We successfully applied selective excitation photoluminescence (PL) and electroluminescence (EL) spectroscopy to analysis of the 1 MeV electron irradiation effects in the MJ cells. The PL peak intensity of band-edge emission from the InGaP2 cell scarcely degraded after irradiation, while that of the GaAs cell decreased considerably. The degradation rate of PL intensity of the Ge cell was less than that of the GaAs cell. The degradation tendencies of EL from the respective sub cells were similar to those of PL measurement. The result of EL spectroscopy paralleled the change in conversion efficiencies of the MJ cells. Shape of the PL spectrum from the GaAs cell changed dramatically except for the emission peak above the band-gap which hardly degraded after the electron irradiation. From these findings, we concluded that the radiation tolerance becomes higher in the order of GaAs, Ge and InGaP2 cells. In addition, we were able to analyze the formation of natural superlattice in the InGP2 cell and determine the doping amount of In in the GaAs cell. We were also able to perform macroscopic and microscopic mappings of PL and EL intensities on the respective sub cells, which were useful for evaluation of the performance uniformity. The characteristic patterns resulting from the dislocations of the cells were observed. We believe that the present study will contribute greatly to the development of highly efficient and highly radiation tolerant MJ cells., 資料番号: AA0049120005}, pages = {22--26}, publisher = {宇宙航空研究開発機構宇宙科学研究本部, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)}, title = {宇宙用多接合太陽電池における放射線照射効果の発光解析}, year = {2005} }