Potentiostatic Deposition and Characterization of Cuprous Oxide Thin Films

Electrodeposition technique was employed to deposit cuprous oxide Cu2O thin films. In this work, Cu2O thin films have been grown on fluorine doped tin oxide (FTO) transparent conducting glass as a substrate by potentiostatic deposition of cupric acetate. The effect of deposition time on the morphologies, crystalline, and optical quality of Cu2O thin films was investigated. 1. Introduction Cuprous oxide is known as P-type semiconductor with a direct band gap that absorbs solar radiation up to 650？nm [1]. belongs to I–VI semiconductor compounds. has been researched as a potential material for photovoltaic applications for several reasons: source materials are abundant and nontoxic, band gap of 1.9–2.2？eV, which can be possibly adjusted by controlling the compositions [2], can be prepared with simple and cheap methods on large scale, and theoretical solar cell efficiency is approximately 20% [3–5]. All of these properties make a suitable material for many potential applications in solar energy conversion, electrode materials, sensors, and catalysis [6–9]. Various methods have been employed for the synthesis of such as thermal oxidation, thermal evaporation, sol-gel, spray pyrolysis, reactive magnetron sputtering, RF magnetron sputtering, and electrodeposition [10–16]. Among them electrodeposition has shown many advantages; it is a simple, economical method for preparation of large area films with good homogeneity, and it allows a good control for the growth parameters. Electrodeposition of involves two steps: the first step is reduction of ions to ions (1) and the second step is precipitation of ions to because of the solubility limitation of ions (2) [17] In this study, the effect of deposition time on the morphologies, crystal and optical quality of electrodeposited thin films is investigated. 2. Experimental Details Electrodeposition of was carried out in a three-electrode setup consisting of platinum wire counter electrode, Ag/AgCl reference electrode, and FTO-coated glass substrate as a working electrode. Before the electrodeposition, the FTO substrates were precleaned by sonication in acetone, isopropanol, and deionized water for 10 minutes, respectively, and then dried at 105°C for several hours. The electrolyte used was composed of 0.02？M cupric acetate and 0.1？M sodium acetate with pH 5.8. The electrodeposition was performed at fixed potential ？0.50？V versus Ag/AgCl reference electrode using Bio-Logic SP-50 potentiostat at 60°C. A series of samples were deposited at 5, 10, 15, and 30 minutes. The morphology of the deposited films at different