Investigation of Transparent Conductive Oxide Al-Doped ZnO Films Produced by Pulsed Laser Deposition

Abstract

High-quality transparent conductive aluminum-doped ZnO (AZO) thin films were deposited on quartz glass substrates using pulsed laser deposition (PLD). We varied the growth conditions in terms of substrate temperature and oxygen pressure. The crystallographic structure and electrical and optical properties of the as-grown AZO films were mainly investigated. In X-ray diffraction (XRD), (002) and (004) peaks were detected, indicating that Al doping did not cause structural degradation of wurtzite ZnO. The AZO films formed at a substrate temperature of 300°C showed a low electrical resistivity of 1.33×10 -4 Ω cm, a carrier concentration of 1.25×10 21 cm -3 and a carrier mobility of 37.6 cm 2 /(V s) at an oxygen pressure of 5 mTorr. A visible transmittance of above 88% was obtained. The AZO films show comparable electrical and optical properties to those of indium tin oxide (ITO) films and are emerging as a potential good challenger to ITO films.