Single Crystal Growth of Arsenic Doped and Phosphorus Doped Cadmium Selenium Telluride (CdSe_xTe_1-x) to Improve CdTe Thin Film Photovoltaics

CdTe is the leading commercial thin film technology that is competing with crystalline Si with about 40% of utility scale PV installation in US being CdTe based. The American company First Solar Inc., the leading manufacturer of CdTe PV sells modules with efficiencies >19%, and cumulative installation has reached 50 GW but that is only about 5% of total PV market [1] . However, unlike Si technology, there is significant headroom for efficiency improvement in CdTe technology as the present record cell level efficiency of 22.3% is only about 70% of the theoretical maximum efficiency of ~32%, the so-called Shockley-Queisser limit [2] .