Preparation Of ZnO Nanostructures By Vacuum Thermal Evaporating Transportation Method

ZnO is a wide direct band gap â…¡-â…¥ semiconductor. There has been great interest in ZnO material due to its prospects in optoelectronics applications, especially in light-emitting diodes, laser diodes and ultraviolet detector. Therefore, ZnO have attracted much attention of many researchers.In this paper, high quality ZnO nanowire arrays and different ZnO nanostructures were successfully fabricated by vacuum evaporating transportation method. The morphology, structure and optical characteristics of as-grown ZnO products were investigated by scan-ning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) analytic technology, respectively. The summary of this thesis is listed as follows:1. In the previous two chapters, I mainly introduce:(1) the basic properties of zinc oxide, such as electrical properties, piezoelectric properties and gas characteristics, etc.;(2) the application and prospects of zinc oxide, such as visible light-emitting semiconductor diodes, semiconductor lasers and semiconductor field effect transistors;(3) two important growth mechanisms of zinc oxide:V-S growth mechanisms and V-L-S growth mechanisms;(4) fabrication methods and characterization methods of zinc oxide:fabrication methods include chemical vapor deposition method, thermal evaporation method and sputtering method; characterization methods include scanning electron microscopy (SEM), X-ray diffraction (XRD), photoluminescence (PL).2. In the latter two chapters, I mainly introduce the experimental procedures and the effects of temperature and catalyst for the growth of ZnO nanostructures. In the experiment, ZnO nanostructures were successfully fabricated by vacuum evaporating transportation method. High-purity ZnO powder was adopted as thermal evaporating source material, the high quality of the ZnO nanowire arrays and the different scales and morphologies of ZnO nanostructures, were fabricated by controlling the furnace pressure, temperature, position of the substrate and other conditions. ZnO nanostructures were investigated by SEM, XRD and PL analytic technology, respectively. When the growth temperature is low, the crystal growth rate is slower, crystal diameter is larger, directionality is better. With the increase of growth temperature, the crystal growth rate increases, the crystal diameter becomes small, directivity becomes bad. It can be clearly observed that the crystals directionality was improved by using the catalyst. Moreover, the improving effect of crystal directionality using seed is not as significant as Au catalytic. These works have a certain reference value for the fabrication of ZnO nanostructures by thermal evaporating transportation method. In the future, By implementing these ZnO nanostructures into semiconductor devices design, one may be able to advantageously impact device performance.