Radiation resistance of super-straight type amorphous silicon germanium alloy solar cells

Performance degradation of super-straight type amorphous silicon germanium alloy (a-SiGe) solar cells due to proton irradiation are investigated using an in-situ current-voltage (I-V) measurement system. The results show that a-Si solar cells have higher radiation resistance than a-SiGe solar cells. Also, the room temperature annealing effects immediately after irradiation are investigated. It is shown that the recovery of the short-circuit current is especially prominent in all the parameters and is more remarkable as the Ge concentration is lower. The variations of dark I-V characteristics are also analyzed. Based on the obtained results, we propose a radiation hardened design of amorphous silicon alloy multi-junction solar cells.