Undoped ZnO film was obtained at ambient temperature using magnetron sputtering and further annealed in vacuum and oxygen atmosphere. A (103) texture was observed on the surface of as-deposited (002)-preferred ZnO film. XPS showed that the majority zinc remains in the valence state of Zn2+, meanwhile the close inspection of O 1s showed that O 1s was composed of components including OI, OII and chemically- or physically-adsorbed oxygen. By the relative intensity of OI/OII and broadened OI the oxygen vacancy concentration variation was considered in different annealing processes. Since the Zn atoms were mostly located in the ZnO1-x matrix, the (002) peak shift in the X-ray diffraction of the vacuum- and oxygen-annealed films was attributed to the variation of the oxygen vacancy concentration, suggesting that the oxygen vacancies in the ZnO thin films were responsible for the decrease of the lattice parameters.

Study of Oxygen Vacancies Influence on the Lattice Parameter in ZnO Thin Film. Li, X., Wang, Y., Liu, W., Jiang, G., Zhu, C.: Materials Letters, 2012, 85, 25-8