Comparison of Cu2ZnSnS4 thin film properties prepared by thermal evaporation of elemental metals and binary sulfide sources

Cu
₂
ZnSnS
₄
(CZTS) thin films have been prepared by thermal evaporation of elemental copper and binary sulfides of zinc and tin. Stacked precursor layers on corning glass substrates were thermally evaporated followed by sulfurization at 560°C under H
₂
S flow to fabricate CZTS films. Six different sequences of stacked layers were studied. Structural, compositional, and morphological characterizations of the resulting films were carried out by x-ray diffraction, scanning electron microscopy, atomic force microscopy and energy dispersive x-ray spectroscopy. Electrical and optical properties were measured via Hall effect, van-der Pauw technique and UV-Vis spectroscopy. Our study showed that the best quality films were obtained with ZnS/Cu/SnS
₂
stacking order of the precursor layers. Details of film fabrication and comparative study of the film properties are discussed. Further study of all the film properties and their corresponding photovoltaic response is presently under investigation and will be reported.