Silicon point contact concentrator solar cells

Recent advances in silicon concentrator solar cells have resulted in cells with 25 percent efficiencies at 20 watts/sq cm of incident sunlight at 26 C. These solar cells are thin, high resistivity cells with an unconventional backside point contact design optimized to operate in high level injection. This paper presents these results and a characterization of some of these cells with respect to wafer thickness. This data verifies predictions from a quasi-three-dimensional model which had predicted a critical thickness dependence. A cell optimized for performance at 36 watts/sq cm incident intensity will be less than 100 microns thick.