Analysis of Radiation Response and Recovery Characteristics of Amorphous Silicon Solar Cells

The radiation response and recovery characteristics of amorphous silicon (a-Si) thin-film solar cells were investigated. The solar cells studied were a-Si/a-Si dual-junction cell and a-Si/a-SiGe cell. The cells were irradiated with monoenergetic protons from 0.05 to 10 MeV to several fluences. For the cells, the displacement damage effects could model the proton-induced degradation much better than the ionizing radiation effects could. Thus, the changes in photovoltaic parameters could be plotted by a single characteristic curve against the displacement damage dose (Dd) even if the proton energy was low enough to create local damage in the active layers. The results indicated that the proton-induced degradations of the a-Si solar cell correlated with the displacement damage effects. In addition, we have reported the recovery characteristics by thermal annealing and light illumination. The electrical outputs of the cells significantly recovered at 70 and 130 degC but were not restored by light illumination