Zinc oxide films by thermal oxidation of zinc thin films

Zinc thin films were deposited onto glass substrates using magnetron sputtering in argon or argon and oxygen mixed atmospheres. These films were then oxidized in air at 600 °C for 1 h to form thin oxide films. ZnO films formed by oxidation of Zn thin films deposited in Ar normally had a dense structure with oxide whiskers on the surface. These films had low optical transmittance in visible light region, but exhibited strong UV and weak defect-related emissions. Addition of oxygen into the sputtering gas led to the partial formation of ZnO in the film, further resulting in the formation of porous and highly transparent oxide films, which showed relatively strong defect-related emission with laser excitation at room temperature. The relations between structural and optical properties were then discussed briefly.