The Future of CdTe Solar Photovoltaics

Solar photovoltaic (PV) energy is a rapidly growing industry and is soon to become the leading contributor for new energy capacity additions in several markets, including the United States. First Solar manufactures thin-film CdTe PV modules and is currently ramping the new utility-power optimized Series 6 technology. Series 6 modules will have initial power up to 440 Watts with an optimized design to lower installation and other balance of system cost. Series 6 enables to take full advantage of high throughput low cost processing of semiconductor materials on glass substrates, compared to the market dominating technologies utilizing wafered crystalline silicon. First Solar’s thin-film CdTe solar cells have been certified at 22% cell efficiency, which means it has achieved approximately 70% of its ultimate entitlement that is defined by the Shockley-Queisser limit for single-junction solar cells. Fundamental work has demonstrated that the defect chemistry, in particular doping efficiency of the p-type semiconductor provides opportunities for future improvement.