Defect Related Green-Red Luminescence of Sb-Doped ZnO Nanorods Grown by Vapor-Phase Oxidation Method.

Vertically aligned undoped and Sb-doped ZnO (ZnSbO) nanorods were grown by the vapor-phase oxidation process on sapphire substrates at 700 °C using Fe as the catalyst. The effect of Sb doping on surface morphology, structural and optical properties of ZnO were studied. The grown undoped and Sb-doped ZnO nanorods have a hexagonal wurtzite structure with preferential c-axis orientation. The as-grown nanorods morphology has shown length of 2-5 μm and a diameter of 100-250 nm. An elongated nanorods and high aspect ratio was observed in Sb-doped ZnO. The undoped ZnO nanorods showed a strong and sharp ultraviolet (UV) emission centered at ~381 nm, whereas Sb-doped ZnO nanorods exhibited two defect related emissions centered at ~530 nm (green) and ~630 nm (red) with a suppressed UV emission. The dominance of the red emission in the nanorods indicates that it exhibits a much higher defect caused by the Sb doping.