Growth of ZnO nanorods on different substrates using hydrothermal method

Abstract

Zinc oxide (ZnO) nanorods have been grown on different substrates, i.e. gold film-coated BK-7 glass (Au-film/BK7), microscope glass slide (MGS), silicon oxide film-coated silicon (SiO2-film/Si), to investigate the effects of different substrates on its material properties. The growth process was started by dipping substrates in zinc acetate solution to fabricate a seed layer, followed by growing the ZnO nanorods in zinc nitrate tetrahydrate solution based on hydrothermal method at 95 °C for 6 hour. In this process, seed layer and ZnO nanorods were annealed at 350 °C for 2 hours. The characterization results using X-ray diffraction and field effect scanning electron microscope showed that ZnO nanorods were successfully grown homogenously and mostly in vertical direction with hexagonal wurtzite structure. The diameter size of ZnO nanorods was significantly influenced by the type of material substrate. ZnO nanorods on Au-film/BK-7 glass have the smallest diameter size of (239±51) nm, while the average diameter size of ZnO nanorods on MGS is of (269±53) nm and ZnO nanorods on SiO2-film/Si have the largest diameter size of (354±80) nm. The effect of substrates on different size of ZnO nanorods may be regarded to the intrinsic thermal conductivity of substrate material. Hence, the synthesis and growth parameters for the different substrates differ from each other and need to be optimized in order to grow ZnO nanostructures