Preparation and Characterization of Cu₂O Thin Films by Electrodeposition in Acidic Media

Abstract

Cu2O is a p-type semiconductor with a band gap of about 2.17 eV. It has an octahedral cubic structure, and has a broad prospect in photocatalysis, battery, and superconductor. The Cu2O thin films prepared by electrochemical deposition method can effectively control the morphology of the sample with low cost and easy operation. Traditionally, the preparation methods of Cu2O thin films mostly use alkaline systems. In this paper, Cu2O thin films were successfully prepared by the electrodeposition method in an acidic system, using copper acetate (Cu(CH3COO)2·H2O) and sodium acetate (CH3COONa) as raw materials. The cyclic voltammetry curve of the solution was tested on an electrochemical workstation. The phase composition of the thin films were characterized using X-ray diffraction (XRD). The surface morphology of the thin films were analyzed by using scanning electron microscope(SEM). The influence of process conditions such as deposition potential, deposition time and electrolyte solution concentration on the preparation of thin films was studied. The results shows that the moderate extension of the deposition time and the increase of the electrolyte solution concentration are beneficial to the preparation of Cu2O thin films. When the deposition potential is −0.1 V, the deposition time is 30 min, and the electrolyte solution concentration is 0.06 mol/L, the continuous and dense Cu2O thin films can be obtained. The XRD peaks of Cu2O thin films correspond to the (110), (111), and (200) crystal planes respectively