Radiation-resistant Multi-layer Silicon Solar Cells

Recent advances in the area of solar cell design promise to deliver thin silicon solar cells with excellent radiation resistance and power to weight ratio. Conventional silicon space cells generally consist of a single p-n junction and are typically 300 m thick. These cells exhibit a substantial degradation in efficiency when exposed to radiation during use in space environments (typically 30 - 40% degradation in efficiency). Advanced conventional, silicon solar cell designs are investigating thinner substrates (around 100 m thick) which will improve the radiation resistance and increase the power to weight ratio of the cell. In this paper we will present initial computer simulation results from a promising new solar cell structure : the multi-layer solar cell, which has a decisively different design. Unlike conventional cells this new cell consists of multiple p and n layers. Our initial modelling indicates that it can achieve quite high efficiencies using only a thin active device thickness (typically 10 - 20 m thick) and exhibits excellent tolerance to radiation damage with typically only an 8% reduction in efficiency at End-of-Life (EOL).