Radiation performance of GaAs concentrator cells for 0.4 to 12 MeV electrons and 0.1 to 37 MeV protons

Gallium arsenide concentrator solar cells have been irradiated with both electrons and protons with a wide variety of energies. The cells are made using OM-VPE growth process with a junction depth of a half micron. All data are taken with bare cells without coverglasses or shielding. Performance data are given at the designed concentration level of 100X AMO. Results are presented in a number of ways, including performance of electrical parameters (P_max, I _SC, and V_OC) as a function of fluence for different electron and proton energies. Critical fluences (defined at a degradation of 25% in P_max) are calculated for each energy level and presented for both electron and proton irradiations