Optical and Solar Cell Properties of Alpha-ray, Proton, and Gamma-ray Irradiated Cu(In,Ga)Se₂ Thin Films and Solar Cells

The effects of alpha-ray, proton, and gamma-ray irradiation on the electrical properties of Cu(In,Ga)Se 2 (CIGS) solar cells and the photoluminescence spectra of CIGS and CuInSe 2 (CIS) thin films were investigated. Particle irradiation using alpha-ray and proton primarily degraded the interfaces of CIGS solar cells, even though the CIS and CIGS thin films did not degraded, in the case of a low irradiation fluence of the order of 10 9 cm -2 . On the other hand, CIS and CIGS showed good tolerance to gamma-ray irradiation because the impact of wave radiation is insufficient to degrade the crystal, in comparison with particle radiation. These results will become the first step toward realizing practical applications of CIGS solar cells in space and clarifying their degradation mechanism.