Thin, light-trapping silicon solar cells for space

Ultrathin silicon solar cells with high efficiency and radiation tolerance can be made by incorporating light-trapping and heterojunction surface passivation. Calculations show that a 2 mu m-thick light-trapping cell remains over 18% efficient after the equivalent of 20 years in geosynchronous orbit. Including a 50 mu m coverglass, the thin cells had, after irradiation, a specific power over ten times higher than that of the baseline design.