Structural, optical and electrical properties of ZnO and ZnO-Al 2 O 3 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.