The recent research and growth in energy efficiency in Cu2ZnSnS4 (CZTS) solar cells

Abstract

Currently the energy harvesting by photoelectric conversion has been efficiently used in energy economics and renewable energy area. The development of solar cell technology is started from the first-generation silicon solar cell to the emerging fourth-generation “inorganics-in-organic” solar cell. Various solar absorber compounds have been used for solar cell manufacturing such as cadmium telluride (CdTe), copper indium gallium selenide (Cu2InGaS4, CIGS), copper indium gallium sulfur selenide (CIGSSe), copper zinc tin sulfide kesterite (Cu2ZnSnS4, CZTS), and copper zinc tin sulfide selenide (CZTSSe). These compounds have conversion efficiencies with some advantages and drawbacks. To overcome the drawbacks and achieve higher conversion efficiency, the efforts have been devoted. With some physical and chemical parametric changes, researchers have got better results in the last 10 years. In the present chapter, research and development on the Cu2ZnSnS4 thin film in the request of highefficiency solar cells is discussed. The effect of various structural and compositional changes in the CZTS; different buffer layers such as cadmium sulfide (CdS), copper sulfide (CuS), zinc sulfide (ZnS), Indium(III) sulfide (In2S3), hybrid Indium(III) sulfide/cadmium sulfide (In2S3/CdS), etc. with interfaces doping into the host material of silver (Ag), sodium (Na), antimony (Sb), etc.; partial substitution of the elements from the host by cadmium (Cd) and selenium (Se); different synthesis; and post-treatments are thoroughly studied. Further, some challenges regarding improving the conversion efficiency of copper zinc tin sulfide (CZTS) solar cells and the future of the solar cell application are discussed.