ZnO nanowires prepared by thermal oxidation of metallic zinc films

ZnO nanowires have been synthesized by thermal oxidation of metallic Zn films. The formation of ZnO nanoneedles was found to be dependent on Zn film thickness and oxidation temperature. Oxidation of 150 nm thick Zn film at 390°C yields the highest density of ZnO nanoneedles. A turn-on field of 5.5 V/¿m and a field enhancement factor of 1587 were achieved. The optimum growth condition is likely due to a balance between stress-induced formation of Zn nanoparticle and oxidation rate that favor the formation of ZnO nanoneedles.