Electrochemical deposition of ZnTe thin films

Abstract

The electrodeposition of zinc telluride (ZnTe) thin films on tin conductive oxide substrates in aqueous solution containing TeO2 and ZnSO4 was studied. The electrodeposition mechanism was investigated by cyclic voltammetry. The appropriate potential region where formation of stoichiometric ZnTe semiconductor occurs, was found to be −1.1 V versus saturated calomel electrode, and the pH was maintained at 3.5 ± 0.1. The crystallographic structure of the deposited film is seen to be cubic with a preferential orientation along the (111) phase. Optical absorption studies reveal a bandgap of 2.26 eV and optical constants (n and k) are evaluated. Scanning electron microscopy imaging was used to study the surface morphology. The composition of ZnTe films was analysed using an electron microprobe analyser, and the results are discussed.