Silicon and gallium arsenide solar cells for low intensity, low temperature operation

This paper describes the possibility of utilising both silicon and gallium arsenide photovoltaic devices to electrically power either spacecraft for interplanetary missions far from the Sun such as the ESA ROSETTA deep space mission, or surface stations for interplanetary exploration such as foreseen in the Mars landing. The investigation particularly deals with the effects induced on solar cell performance by typical deep space environmental conditions such as low temperature and low solar intensities. Efficiencies of 25% at -100 C, 0.11 SC, of 27% at -150 C, 0.11 SC and still 26% at -150 C, 0.03 SC have been achieved for best HI-ETA/NR-LILT silicon solar cells with an area of 3.78 cm×6.19 cm and efficiencies of 24.1% at 0.11 SC, -130 C and 23.8% at 0.03 SC, -150 C for GaAs solar cells with an area of 2 cm×4 cm