Preparation and formation mechanism of smooth and uniform Cu_2O thin films by electrodeposition method

摘要

Smooth and uniform Cu_2O 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 Cu_2O thin films were achieved by electrodeposition under the potential of -0.1V (vs. SCE) with 0.5mM thiourea, which exhibited obvious absorbance and photocurrent response in visible light range. In addition, as the concentration of thiourea increased, the density of Cu_2O thin films decreased. Based on this, the thiourea assisted growth process was proposed as a plausible mechanism for the formation of smooth and uniform Cu_2O thin films.