Rare-metal free thin film solar cell

Cu/sub 2/ZnSnS/sub 4/ (CZTS) thin films have been successfully formed on a soda lime glass substrate by vapor phase sulfurization of precursors of E-B evaporation. This semiconductor does not contain any rare-metal such as indium. In this study, we estimated the optical band gap energy as 1.45 eV and the optical absorption coefficient was in the order of 10/sup 4/ cm/sup -1/. From these optical properties, this CZTS film is very suitable for thin film solar cells. Fabricated solar cells, Al/ZnO/CdS/CZTS/Mo/soda lime glass, showed an open circuit voltage up to 522 mV.