Characterization of NiO thin film grown by two-step processes

NiOx thin films were grown on quartz-glass substrates by two-step process: oxidation of metal Ni thin film which was obtained by vacuum evaporation method. The structural, optical and electrical properties of NiOx thin film were investigated by X-ray diffraction, absorption spectra and Hall measurement, respectively. The oxidation temperature could influence the structural, electrical and optical properties of NiOx thin film. At lower oxidation temperature (623K), the oxidation process was not finished completely. With the increase of oxidation temperature, Ni thin films were totally oxidized into p-type NiO thin films and the optical absorption edge became steeper. Furthermore, the conductivity and carrier concentration of p-type NiO thin film decreased with the increase of oxidation temperature.