Effects of supply time of Ar gas current on structural properties of Au-catalyzed ZnO nanowires on silicon (100) grown by vapor-liquid-solid process

ZnO nanowires were grown on Au-coated Si (1 0 0) substrates by the method of vapor-liquid-solid (VLS) growth processing technique. The effects of supply time of Ar gas current on morphology and microstructure of Au-catalyzed ZnO nanowires were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. The results showed that the morphologies of ZnO nanostructures strongly depended on the time of flowing Ar gas. When the time of flowing Ar gas was 90 s, ZnO showed nanowires with hexagonal structure. Their diameters and lengths were 160 nm and 20 mu m, respectively, on average, and the Raman scattering peak located at 438 cm(-1) reached maximum intensity. The results also showed that the ZnO growth could be patterned by controlling the initial position of Au-coated area on the Si substrates. (C) 2006 Elsevier B.V. All rights reserved.