1 MeV electron irradiation effects on GaAs solar cell grown on Si substrate

摘要

GaAs-on-Si solar cell will be playing an important role for space applications because Si substrate is low-cost, lightweight and large-area also its radiation tolerant behavior. We have reported the radiation effects of high-energy electron (1 MeV, fluences of 1×10{sup}13, 1×10{sup}14, 1×10{sup}15 and 1×10{sup}16 cm{sup}(-2)) on GaAs layers on Si and GaAs substrates grown by metal organic chemical vapor deposition. After the irradiation, there are no considerable changes for barrier height and ideality factor in the diodes on Si substrate. The number of trap level increases more in case of GaAs/GaAs compared with GaAs/Si. The solar cell parameters such as short-circuit current (Isc), open circuit-voltage (Voc), fill factor (FF) and conversion efficiency are studied under dark and AMO conditions. The degradation rate of Voc and Pmax for GaAs/GaAs solar cell is faster than GaAs/Si solar cell at higher fluences. The slow degradation of GaAs/Si solar cell is due to slow generation of As vacancy in the base layer. These experimental results suggest that GaAs solar cell on Si substrate has higher radiation resistance compared with GaAs solar cell on GaAs substrate under 1 MeV electron irradiation.