6 0Co γ-ray and electron irradiation damage of GaAs single crystals and solar cells

Abstract

⁶⁰Co γ‐ray and high energy electrons (0.8–4 MeV) irradiation damage of GaAs solar cells were examined. Changes in minority carrier diffusion length in irradiated GaAs single crystals were also investigated by electron beam and ⁶⁰Co γ‐ray‐induced current methods for solar cells. Damage constant of p‐GaAs is smaller than that of n‐GaAs. Equivalent damage rate in GaAs due to electron irradiation to ⁶⁰Co γ‐ray irradiation damage was clarified experimentally and theoretically. Experimental results for radiation damage of GaAs solar cell were also in satisfactory agreement with theoretical values, calculated from change in minority carrier diffusion length due to irradiation. Radiation damage in GaAs solar cells can be evaluated by using radiation damage data in GaAs single crystals. In‐depth profiles for electron irradiation damage in GaAs and annealing behavior of radiation damage in GaAs were also examined.