Preparation and characterization of Cu2ZnSnSe4 thin films by selenization of electrodeposited metal precursors

Cu2ZnSnSe4 thin films were prepared by selenization of electrodeposited Cu-Zn-Sn precursors. The Cu-Zn-Sn precursors were electrodeposited on the Mo-coated glass substrates from an electrolyte containing copper sulfate, zinc sulfate, tin (II) sulfate at a fixed potential between -1.2V and -1.25V vs. saturated calomel electrode, then the Cu2ZnSnSe4 thin films were obtained by selenizing Cu-Zn-Sn precursors in elemental selenium atmosphere at different temperatures. The structure, composition and optical properties of the films were investigated by X-ray diffraction, Energy dispersive spectrometry and UV-VIS absorption spectroscopy. The CZTSe films have a stannite structure and an optical band-gap about 1.6 eV which is suitable for fabricating solar cells.