Aluminum-doped ZnO polycrystalline films prepared by co-sputtering of a ZnO-Al target

Abstract

Aluminum-doped Zinc oxide polycrystalline thin films (AZO) were grown on 7059 Corning glass substrates at room temperature by co-sputtering from a ZnO-Al target. The target was designed as follows, high purity elemental Aluminum was evaporated onto a ZnO target covering small areas. The structural, optical, and electrical properties were analyzed as a function of Al content. The Al doped ZnO polycrystalline films showed an n-type conductivity. It was found that the electrical resistivity drops and the carrier concentration increases as a consequence of Al incorporation within the ZnO lattice. In both cases the changes are of several orders of magnitude. From the results, we conclude that, using these ZnO-Al targets, n-type Al doped ZnO polycrystalline films with high transmittance and low resistivity can be obtained.