Development activities of GaAs space solar cells and photovoltaic assemblies for high temperature applications

Purpose of this work was the selection of materials and manufacturing processes able to withstand the high temperature conditions typical of interplanetary space missions towards the Sun (e.g. Mercury). There are only few experiences reported on this subject by the scientific community. The limited time (18 months) and funding available for this study imposes a developing approach using as much as possible existing technologies. This goal is achieved by means of an optimisation work performed on the already available space solar cells and photovoltaic assembly (PVA). The studies were developed in two different paths: experiments have been carded out through tests at CIC and coupon level; analyses based on a mathematical modelling of PVA concepts to confirm the experimental data. The above led to a "high temperature and insolation" PVA baseline technology selection that is now under testing. This campaign includes tests at CIC level (single and triple-junction GaAs calls) and at coupon level (Carbon and Aluminium substrate skins) and it will be completed within the end of year 2002.