Degradation behavior of flexible a-Si/a-SiGe/a-SiGe triple junction solar cells irradiated with 20-350 keV protons

Electrical performance degradation of a-Si/a-SiGe/a-SiGe triple-junction solar cells due to irradiation of protons with different energies and their performance recovery at room temperature just after irradiation are reported. The current-voltage characteristics are measured in-situ and the results show that all the parameters recover with time after proton irradiation is stopped. In particular, the short-circuit current remarkably recovers. It is also shown that the degradation is scaled by a unit of displacement damage dose independent of proton energy. This indicates that the proton-induced degradation is mainly caused by the displacement damage effect.