Refined carbothermal reduction approach for large scale, uniform growth of vertically aligned ZnO nanowires

Abstract

For a large scale, uniform growth of vertically well-aligned zinc oxide (ZnO) nanowires (NWs), a carbothermal reduction process was refined. Depending on how ZnO and graphite powders are loaded, i.e., stacked versus mixed states, the NWs show strikingly different growth behaviors. A newly introduced ZnO/graphite stacked source was found to be superior to a conventional mixed source with respect to the degree of vertical alignment and uniformity presumably due to the controlled (steady, slow) generation of Zn species at the ZnO/graphite boundaries. Effects of growth temperature, Ar gas flow, and weight of source materials on growth behaviors of ZnO NWs are investigated, and their optical and structural properties are characterized. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim