Characterization of CuAlO2 films prepared by dc reactive magnetron sputtering

Thin films of copper aluminum oxide (CuAlO₂) were prepared on glass substrates by dc magnetron sputtering at a substrate temperature of 523 K under various oxygen partial pressures in the range 1 × 10⁻⁴–3 × 10⁻³ mbar. The dependence of cathode potential on the oxygen partial pressure was explained in terms of oxidation of the sputtering target. The influence of oxygen partial pressure on the structural, electrical and optical properties was systematically studied. p-Type CuAlO₂ films with polycrystalline nature, electrical resistivity of 3.1 Ω cm, Hall mobility of 13.1 cm² V⁻¹ s⁻¹ and optical band gap of 3.54 eV were obtained at an oxygen partial pressure of 6 × 10⁻⁴ mbar.