InAsP cells for solar thermophotovoltaic applications

High temperature wide band gap InAsP cells have been specifically designed and fabricated for operating temperatures up 250/spl deg/C to match with selective emitters operating near 1 μm in a TPV system. An important assumption is that the emitters can be heated up to the range of 1400 K to 2000 K by either solar concentrators or some other heat source. The efficiency of a selective emitter, which can be selected depending on the emitter operating temperatures, will be significantly higher than either a blackbody or a graybody emitter. The key for the TPV success is that the match between the band gap and selective emission must occur at the cell operating temperature. An appropriate cell band gap needs to be carefully selected; so when the band gap shrinks at the operating temperature, the desired match can be achieved. Two types of InAsP cells were investigated for this concept. The performance of these cells at elevated temperature and energy conversion efficiency are reported in this paper.