Thermal annealing of GaAs concentrator solar cells

The thermal annealing of GaAs concentrator cells for space power after electron irradiation is reported. Results are given for cells annealed at 150°C, 200°C, and 250°C. Isochronal annealing was done for 20 min intervals up to 350°C. For cells irradiated with electrons of energies between 0.7 and 2.3 MeV, the recovery decreases with increasing electron energy. Isothermal and isochronal annealing produce the same recovery. Cells irradiated to 3×10¹⁵ or 1×10¹⁶ e/cm² recover to similar unannealed fractions. Significant annealing is seen starting at 150°C, although very long times are required