Proton irradiation effects on silicon heterojunction solar cells with MoOx selective contacts

Abstract

In this study, we investigate the effects of proton irradiation on silicon-based heterojunction and molybdenum oxide (MoOx) selective contact solar cells. The main idea is to study their potential application in small satellites for measurement and monitoring. The irradiation dose simulates the aggressive environment found in Low Earth Orbit (LEO), where many satellites currently use Group III-VI (GaInP/GaAs/Ge) solar cells due to their superior efficiency, albeit at a higher cost. The experimental approach includes fabrication, irradiation, and characterization methods. Our results show a decrease in fill factor (F.F.) and overall efficiency after irradiation, mainly caused by a decrease in shunt resistance and an increase in series resistance. In addition, open-circuit voltage (Voc) and short-circuit current (Isc) may be affected by displacement damage defects caused by the irradiation process within the active region or by the formation of new point defects.