Degradation prediction using displacement damage dose method for AlInGaP solar cells by changing displacement threshold energy under irradiation with low-energy electrons

Abstract

Performance degradation prediction for space solar cells under irradiation with low-energy electrons is greatly affected by displacement threshold energy (Ed) when a displacement damage dose (DDD) model is used. According to recent studies, the Ed of P atoms is much lower than the conventional Ed value in InP-type solar cells irradiated with low-energy electrons. This indicates that the value of Ed typically used in DDD model leads to significant error in performance degradation prediction. In this study, degradation of AlInGaP solar cells is observed after irradiation with 60–500 keV electrons. The results suggest that the Ed of P atoms in AlInGaP solar cells is much smaller than the conventionally used Ed value. By using the DDD model with the Ed value obtained in this study (Ed = 3.5 eV for P), we demonstrated that the performance degradation predicted by the DDD model agrees well with the experimental results.