XRD, XPS, and optical characterizations of Al-doped ZnO film grown on GaAs substrate

A ZnO:Al (10%) thin film was prepared on GaAs(100) substrate by using a pulsed filtered cathodic vacuum arc deposition (PFCVAD) system. The ZnO:Al thin film was thermally annealed for 1 h at 2 different temperatures in air. The film structure was investigated as a function of annealing temperature by X-ray diffraction (XRD). ZnO:Al film annealed at 500 ° C by PFCVAD method resulted in an amorphous film. However, after annealing ZnO:Al film at 600 ° C, it showed (100) and (002) peaks at around 32 ° and 34 ° , respectively. The chemical state of ZnO:Al (AZO) film on GaAs substrate was investigated by using X-ray photoelectron spectroscopy (XPS). The dependence of optical properties on annealing was investigated by using a UV-VIS-NIR spectrophotometer. We also obtained the energy gap of ZnO:Al thin film by diffused reectance spectra using the Kubelka-Munk function.