Synthesis of CZTS thin films from binary precursors stacking by chemical bath deposition for solar cell applications

Abstract

Kesterite Cu2ZnSnS4 thin films were synthesized by chemical bath deposition without using the sulfurization/selenization process. The precursors were stacked following the deposition sequence: CuS/SnS/ZnS/substrate. The synthesized samples were annealed at 400, 450, and 550 °C in a vacuum condition. The structural analysis by XRD and Raman Spectroscopy confirmed the Cu2ZnSnS4 phase. The optoelectronic characteristics of the samples synthesized in this work were similar to those values of these kesterite-type semiconductors synthesized by other methods. The kesterite semiconductor bandgap was ranging from 1.45 to 1.49 eV with a conductivity of 10-3(Ω cm)-1, depending on the thermal treatment conditions. It is feasible to consider the synthesis of kesterite Cu2ZnSnS4 by chemical bath deposition method of binary precursors. The appropriate thermal treatment temperature is 450 °C for obtaining adequate optoelectronic characteristics for solar cell applications.