Electrodeposition of ternary CuxSnySz thin films for photovoltaic applications

ABSTRACT We exploited alternated electrodeposition of Cu, Sn and S to obtain CuxSnySz thin films. These materials are kesterite‐type chalcogenides that have attracted a relevant interest from worldwide researchers as low cost and high conversion efficiency solar cell devices. Films were grown on silver substrate, controlling the growth of the electrodeposited structures at the nanometric level. The obtained films were characterized by diffuse reflectance spectroscopy, voltammetric stripping and atomic force microscopy. Experimental bandgap energies resulted linearly modulated by changes of chemical composition and thickness. On the basis of these results, we candidate electrodeposition as a room temperature method to obtain thin films for solar cell technology with low energy investment and negligible environmental impact. Copyright © 2013 John Wiley & Sons, Ltd. In this study, a new approach to synthesize thin films of ternary copper and tin sulfides, technologically relevant for photovoltaic semiconductors, characterized by low cost of raw materials and absence of toxicity, is proposed. This approach is established within the electrodeposition ECALE technique, which enables the opportunely change of the sequence of deposition and of the number of cycles to obtain CuxSnySz thin films with different composition and thickness, precisely adjusting the bandgap depending on the target device.