Change in the electrical performance of GaAs solar cells with InGaAs quantum dot layers by electron irradiation

The radiation response of GaAs PiN solar cells with 50 stacked layers containing self-aligned In0.4Ga0.6As quantum dots (QDs) was compared to that of GaAs PiN solar cells with non QD layers. Those solar cells were radiated with 1 MeV electrons up to 1×1016/cm2, and the change in their electrical characteristics under AM 0 was investigated using an in-situ measurement technique. After electron irradiation at 1×1016/cm2, the value of open circuit voltage (VOC) for the In0.4Ga0.6As 50 QD and the non QD solar cells remained 90 and 80% of the initial value, respectively. On the other hand, the values of short circuit current (ISC) and maximum power (PMAX) for the 50 QD solar cells became approximately 80 and 55% of the initial value by electron irradiation at 1×1016/cm2, respectively, although the non QD solar cells showed 95% for ISC and 63% for PMAX after the irradiation. The recovery of the electrical characteristics of both the InGaAs 50 QD and the non QD solar cells irradiated with electrons at 1×1016/cm2 were observed under AM0 light illumination at RT.