Ultra-fine UV photoluminescence emission at room temperature from an individual ZnO nanorod

Highly-crystalline zinc-oxide (ZnO) nanorods and nanowires with hexagonal cross sections are grown on a sputtered ZnO thin film as buffer layer, using physical vapor deposition (PVD) technique in the absence of any catalyst. For the experimental setup, a double tubes furnace at atmospheric pressure is utilized. The structural characteristics of the samples are studied by using field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). The optical properties of grown nanorods are investigated by using micro photoluminescence (PL) spectroscopy. The results show that high-quality ZnO nanostructures can be obtained by control of the super saturation conditions during the growth process while the XRD and EDS results reveal that the grown nanorods are single-phase hexagonal ZnO with a perfect elemental stoichiometry. Micro PL measurement of a single nanorod results in fine spectra, in which, it exhibits a sharp ultraviolet (UV) emission bands, corresponding to the near-band-edge (NBE) emission of crystalline ZnO, without any peak in the green or the orange region, which is normally related to crystal defects.