Structural and optical studies on dc reactive magnetron sputtered Cu2O films

Abstract

Cuprous oxide (Cu2O) thin films were deposited by dc reactive magnetron sputtering technique onto glass substrates by sputtering of pure copper target in a mixture of argon and oxygen gases under various oxygen partial pressures in the range 8×10−3–1×10−1 Pa at a constant substrate temperature of 473 K and a sputtering pressure of 4 Pa. The dependence of cathode potential on the oxygen partial pressure was explained in terms of cathode poisoning effect. The influence of oxygen partial pressure on the structural and optical properties of Cu2O films was systematically studied. Single phase films of Cu2O were obtained at an oxygen partial pressure of 2×10−2 Pa. The films formed at an oxygen partial pressure of 2×10−2 Pa were polycrystalline with cubic structure and exhibited an optical band gap of 2.04 eV.