Study on the Bifacial Ultrathin CdTe Solar Cell With ZnTe:N/IWO Composite Transparent Back Electrode

Fabrication of bifacial translucent solar cell is a promising technology for the development of building integrated photovoltaics and the construction of tandem solar cell. In this work, cadmium telluride (CdTe) polycrystalline thin films with a thickness of 1 μm were prepared by using close space sublimation system while nitrogen-doped zinc telluride (ZnTe: N) and tungsten-doped indium oxide (IWO) layers were deposited by using magnetron sputtering and reactive plasma deposition technology, respectively. After analyzing the optical and electrical properties of films and optimizing their deposition processes, a bifacial ultrathin solar cell with a 7.1% back illumination conversion efficiency was developed, which was currently the best back illumination efficiency for CdTe solar cell with an absorption layer thickness of no more than 1 μm. Furthermore, the bifacial ultrathin CdTe solar cell with ZnTe:N/IWO composite transparent back electrode can achieved a maximum theoretical efficiency of up to 20% under the back illumination by employing SCAP software simulation design.