Electron and proton irradiation of GaSb infrared solar cells

Gallium antimonide (GaSb) infrared solar cells were exposed to 1 MeV electrons and 0.2-1 MeV protons up to fluences of 1×10¹⁵ cm^-2 and 1×10¹² cm^-2 respectively. In between exposures, current-voltage and spectral response curves were taken. The GaSb cells were found to degrade slightly less than typical GaAs cells under electron irradiation, and calculations from spectral response curves showed that the damage coefficient for the minority carrier diffusion length was 3.5×10 ^-8. The cells degraded faster than GaAs cells under proton irradiation, but the top cell and coverglass are expected to protect the GaSb cell from most damaging protons. Some annealing of proton damage was observed at low temperatures (80-160°C)