Preparation and formation mechanism of smooth and uniform Cu2O thin films by electrodeposition method

Smooth and uniform Cu2O thin films were prepared by electrodeposition on Sn-doped indium oxide substrates (ITO) in Cu(Ac)(2) electrolytes with thiourea addition. The influence of deposition potential and thiourea concentration on the formation of these thin films was investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results show that smooth and uniform Cu2O thin films were achieved by electrodeposition under the potential of -0.1 V (vs. SCE) with 0.5 mM thiourea, which exhibited obvious absorbance and photocurrent response in visible light range. In addition, as the concentration of thiourea increased, the density of Cu2O thin films decreased. Based on this, the thiourea assisted growth process was proposed as a plausible mechanism for the formation of smooth and uniform Cu2O thin films. (C) 2012 Elsevier B.V. All rights reserved.