The effect of source temperature on morphological and optical properties of ZnO nanowires grown using a modified thermal evaporation set-up

In this paper the effect of source temperature on the morphological and optical properties of ZnO nanowires using a thermal evaporation set-up was investigated. A simple horizontal double-tube system was used to grow the ZnO nanowires. The nanowires with different morphology were obtained by the same substrate temperature and different source temperatures. Vertical and aligned nanowires with hexagonal shape were grown at the source temperature of 950 °C, while the nanowires with spear shape were grown at the source temperature of 1050 °C. The diameters of nanowires were the same for the both set of nanowires, approximately. In addition, characterizations showed that the growth direction of the both set of nanowires was [0001]. Room temperature photoluminescence and Raman spectroscopy studies demonstrated that the ZnO nanowires were grown in lower source temperature zone had better crystalline quality and optical properties than those were grown by higher source temperature.

Research highlights
► In this study, ZnO nanospears fabricated for first time.
► We observed, source temperature is an important factor to obtain different morphologies.
► Vertical and aligned ZnO nanowires grown on Si substrate by PVD method.