X-ray diffraction spectroscopy and X-ray photoelectron spectroscopy studies of Cu-doped ZnO films

Cu-doped ZnO films have been prepared using direct current co-reactive magnetron sputtering technique at different oxygen partial pressures. The microstructure and the chemical state of oxygen, copper and zinc in ZnO films was investigated by X-ray diffraction spectroscopy (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The results indicate that ZnO films with moderate Cu doping can obtain wurtzite structure with strong c-axis orientation. The crystal quality of the ZnO:Cu films can also be enhanced with moderate enrichment of oxygen in the sputtering process. The XPS spectra of zinc, oxygen and copper results also show that moderate enrichment of oxygen is helpful for the stoichiometry of the ZnO:Cu films, which is consistent with the analysis results of XRD.