Structural, optical and electrical properties of ZnO and ZnO-Al2O3 films prepared by dc magnetron sputtering

Abstract.

ZnO and ZnO-Al₂O₃ thin films were prepared by dc magnetron sputtering and their structural, optical and electrical properties were studied comparatively. It is discovered that the ZnO-Al₂O₃ thin films remain transparent in a shorter wavelength range than the ZnO films, resulting from the increase of their band gap. Their resistivity decreases by seven orders of magnitude, which is caused by doping of Al to ZnO grains in the film. Preferential orientation of ZnO grains in the ZnO-Al₂O₃ thin films deteriorates because of the existence of Al₂O₃ impurity phase in the film.