Abstract
Cu2ZnSnS4 (CZTS) is one of the promising materials for low cost thin film solar cells, because of suitable band gap energy around 1.5 eV, and the large absorption coefficient over 104 cm−1. All constituents of this film are abundant on the crust of the earth, and they are not toxic. In 1996, we reported a fabrication process of CZTS films by sulfurization of EB evaporated precursors. We formed a new type of thin film solar cells having the structure of SLG/Mo/CZTS/CdS/ZnO: Al/Al and achieved the conversion efficiency of 0.66% for the first time. Recently, using CZTS compound target, we achieved over 6.4% efficiency with CZTS films prepared by the single sputtering followed by sulfurization. In this article, the development of CZTS-based thin film solar cells will be reviewed.
