Degradation modeling of InGaP/GaAs/Ge triple-junction solar cells irradiated with various-energy protons

Sato, Shinichiro; Miyamoto, Haruki*; Imaizumi, Mitsuru*; Shimazaki, Kazunori*; Morioka, Chiharu*; Kawano, Katsuyasu*; Oshima, Takeshi

Degradation modeling of InGaP/GaAs/Ge triple-junction (3J) solar cells subjected to proton irradiation is performed with the use of a one-dimensional optical device simulator, PC1D. By fitting the external quantum efficiencies of 3J solar cells degraded by 30 keV, 150 keV, 3 MeV, or 10 MeV protons, the shortcircuit currents () and open-circuit voltages () are simulated. The damage coefficients of minority carrier diffusion length () and the carrier removal rate of base carrier concentration () of each subcell are also estimated. The values of and obtained from the calculations show good agreement with experimental values at an accuracy of 5%. These results confirm that the degradation modeling method developed in this study is effective for the lifetime prediction of 3J solar cells.