Effect of complexing agent on the morphology and annealing temperature of CZTS kesterite thin films by electrochemical deposition

Abstract C u 2 Z n S n S 4 kesterite thin films have been electrochemically deposited on indium doped tin oxide ( I T O ) coated glass substrates from an aqueous electrolyte solution containing C u S o 4 , Z n S o 4 , S n S o 4 and N a 2 S 2 O 3 precursors in one step deposition. The purpose of this work is to reduce the cost of fabrication of C Z T S thin films with good crystallinity by investigated the effect of complexing agent N a 2 S o 4 with N a 3 C 6 H 5 O 7 on annealing temperature of C Z T S thin film. Based on the results it was found that good crystal structure was achieved at temperature 350 °C, that is below the reported annealing temperature in the literature. The electrodeposition process was maintained at room temperature with a working potential set at −1.05 V vs. A g / A g C l . The annealed C Z T S films were characterized by X-ray diffraction revealed the formation of a crystalline phase C Z T S with major and intense peaks. Scanning electron microscopy ( S E M ) analysis stick to E D S show compact and uniform surface morphology with a spherical crystalline geometry and near stoichiometry metal atomic ratio for the different samples prepared. Atomic force microscopy ( A F M ) analysis confirms these results. From UV–visible spectroscopy, bandgap of around 1.5 e V was estimated for the kesterite thin films.