Influence of growth temperature on morphological, structural and photoluminescence properties of ZnO nanostructure thin layers and powders deposited by thermal evaporation

摘要

Zinc oxide (ZnO) nanostructures were grown as thin films on the p-silicon (100) wafer and also in the form of powder inside the boat by heating (550-950 degrees C) zinc powder in the presence of oxygen without any catalyst or additives, using the thermal evaporation method. The field-emission scanning electron microscopy images, as well as energy-dispersive X-ray spectroscopy and X-ray diffraction spectra, indicate that although the grown samples are covered with various nanostructure shapes, such as nanowires, nanorods, Hower-like nanostructures and microcages, all have a reasonable stoichiometric composition in the polycrystalline wurtzite phase along (002) in the thin layer samples and along (101) in the powder samples within the boat. The room-temperature photoluminescence spectra of the thin layer samples revealed not only the ultraviolet (UV) emission blue shift of the samples with an increase in the growth temperature, but also found that the emission intensity ratio of UV/visible (similar to 510 nm) has a maximum and minimum, corresponding to that grown at 750 and 950 degrees C, respectively.