Deposition and characteristics of CdO films with absolutely (200)-preferred orientation

Abstract CdO crystal thin films with (200)-preferred orientation have been prepared on Si and glass substrates by dc reactive magnetron sputtering method. At an optimum substrate temperature of 375 °C, the film has the best crystal quality. By the electrical and transmittance measurements the film shows large carrier concentration of 2.00×1020/cm3, Hall mobility of 64 cm2/V s, resistivity of 4.87×10−4 Ω cm and a high average transmittance over 80% in the visible region together with a direct band gap of 2.43 eV. In view of the Burstein–Moss (BM) shift, theoretical calculations show that the film has a direct band gap of 2.17 eV, close to its intrinsic band gap of 2.2 eV. The photoluminescence (PL) measurement shows that the pure CdO film has no luminescence behavior, but it can alloy with ZnO to realize its applications in luminescent devices.