On-sun concentrator performance of GaInP/GaAs tandem cells

The GaInP/GaAs concentrator device has been adapted for and tested in a prototype "real-world" concentrator power system. The device achieved an on-sun efficiency of 27%/spl plusmn/1% in the range of approximately 80-400 suns with device operating temperatures of 32/spl deg/C to 50/spl deg/C. We discuss ways of further improving this performance for future devices.