Large-scale synthesis of aligned hexagonal ZnO nanorods using chemical vapor deposition

Aligned hexagonal ZnO nanorods were densely grown on a pure Si substrate. The synthesis involved a simple and low cost process based on thermal evaporation of ZnS powder, followed by oxidization without the presence of any catalyst. The product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and room-temperature cathodoluminescence (CL) spectroscopy. We found that the ZnO nanorods were pure, well-aligned, with diameters of 100-300 nm and length of about 10 mum. One strong green-light emission peak at 538 nn was observed. The origin of this cathodoluminescence might be ascribed to the existence of defects such as the single ionized oxygen vacancies formed in the ZnO nanorods. (C) 2004 Elsevier B.V. All rights reserved.