520 MeV proton irradiation effects on GaAs/Ge space solar cells

High-energy proton irradiation effects on GaAs/Ge solar cells for space use are studied. The cells are irradiated by protons with an energy of 5-20 MeV up to a fluence ranging from 1 x 109 to 7 x 1013 cm-2, and then the change of the photovoltaic performances is measured at AMO. It is shown that the performances of the cells keep no change under 1 x 109 cm-2 irradiation. Above 1 x 109 cm-2 irradiation, Isc, Voc and Pmax degrade, as proton irradiation fluence increases. But the higher the proton energy, the less the degradation of Isc, Voc and Pmax