Effect of the O-2/N-2 Ratio on the Growth of ZnO Nanostructures on c-Plane Sapphire Substrate via Thermal Evaporation Technique

摘要

ZnO nanostructures were grown on c-plane sapphire substrate in an oxygen and nitrogen gas environment at 1000 degrees C by thermal evaporation of Zn powder without using catalyst. The ZnO nanostructures were synthesized at different O-2/N-2 ratios in order to investigate the effect of O-2/N-2 ratio in ambient gas on the morphology, crystal structure and cathodoluminescence of ZnO nanostnictures. No nanostructures were grown on the substrate in a N-2 environment. As the ratio of O-2 to N-2 increased, ZnO nanostructures with wire shape began to be grown on the substrate. In addition, tilted nanowires, which were grown with tilt angles with respect to the substrate plane, were observed. With further increasing the ratio of O-2 to N-2, the size of nanostructures increased. The intensity of visible emission in CL spectra increased with the increase in the ratio of O-2 to N-2.