Low intensity low temperature performance of advanced solar cells

Renewed interest in the use of photovoltaics for deep space applications has spurred the development of silicon cells designed for low intensity low temperature (LILT) operations. It also raises questions about the performance of existing multi-junction GaInP₂/GaAs/Ge cells. Previous tests have indicated that multi-junction cells exhibit typical LILT degradation features. However, the latest triple-junction cells had not been tested. Performance data are particularly relevant for proposed operations in high-radiation environments (e.g. Jupiter orbiters), where little previous data exist. Results are presented showing the performance of several cell technologies under unirradiated and irradiated conditions at a series of temperatures and intensities. While some general trends hold among similar products, significant differences are observed between the various manufacturers.