Study Of ZnO Nanostructures Prepared By Aqueous Solution

ZnO is a kind of multifunctional semiconductor material with the wurtzite structure. The band gap energy of ZnO is 3.37 eV and its exciton binding energy is 60 meV, thus ZnO is expected having the ability of stimulated emission at room temperature. ZnO has many special properties, such as high electron mobility, good piezoelectric, and fluorescence, etc. which are widely used in light emitting diodes, field effect transistor, gas sensors, solar cells and light catalytic field. In recent years, one of hot topics is to prepare one-dimensional (1D) ordered nanostructures with excellent properties by combing micro-processing with a subsequent growth technology. There are two Challenges:one is the low-cost,preparation at large area, and the other is to the control in the growth of ZnO nanostructures, including the location, size, direction and uniformity.In this paper, two kinds of templates, which are based on the self-assembly nanospheres lithography, were used for controlling the formation of ID ZnO ordered nanostructures. Using scanning electron microscope (SEM), room temperature photoluminescence (PL), and ultraviolet-visible spectroscopy, the surface morphology and optical properties of the ZnO nanostructures were characterized. In addition, we explored the influence of growth conditions on the ZnO nanostructures. The main results are summarized as follows:The growth of latticed ZnO nanorod arrays:Using the patterned ZnO seed layers prepared by the self-assembly polystyrene microspheres, the latticed 1D ZnO nanorod arrays were grown through an aqueous solution process. SEM results showed that the diameters of the polystyrene microspheres and the time for reactive ion etching are two crucial parameters to control the formation of the patterned ZnO seed layers. On the other hand, the aqueous solution process determines the morphology of ZnO nanorods. In addition, we dicussed the dependence of the room-temperature PL spectra on the diameter of the ZnO nanorods.ZnO nanoflower arrays:Using the self-assembly polystyrene microsphere arrays with ZnO seed layers, ZnO nanofowler arrays consisting of 1D ZnO nanorods were grown through an aqueous solution process. Methylene blue was used as the target to test the photocatalytic efficiency of different ZnO nanorod array under UV irradiation. It is found that the photocatalytic activity of ZnO nanorod array was ascribed primarily to the efficiently irradiating area of ZnO nanorods.