| This paper is written on the experiment preparing zinc oxide particle films, micron flowers, microspheres and nanorod array structure on a substrate by continuous ion adsorption and reaction(SILAR), the hydrothermal method and microwave method. The experiment is conducted to study the influence exerted by precursor concentration, reaction time and the seed layer spin-coated on the morphology, the luminescent properties of zinc oxide nanostructures and try to illustrate the growth mechanism of ZnO nanorod arrays.The main experimental findings are as follows:(1) A dense zinc oxide nano-particle films has been prepared on silicon substrates by continuous ion adsorption and reaction method. the film is dense and the particle size stands at the nano scale; You can see the three peaks of zinc oxide film and make sure the film is a hexagonal wurtzite ZnO crystal. It can be found that zinc oxide nanoparticles film (002) has a plane-preferential growth trend. It can be seen from the photoluminescence spectrum that there are strong peaks at a wavelength of380nm with weak emission peak in the visible light region, which shows there are few defects level caused by the oxygen vacancy and interstitial in the prepared zinc oxide thin films.(2) Zinc oxide micron flowers and microspheres have been prepared on silicon substrates by low-temperature hydrothermal method. SEM, XRD and PL show that Zinc oxide micron flowers and Microspheres are hexagonal wurtzite structure crystal with integral structure and luminescent properties. When growing for2.5h in the low-temperature hydrothermal environment, the sample obtained takes on needle micron flower structure. However, when growing for12h under the same condition, the sample comes out to be zinc oxide microspheres. This result indicates with the increase of growth time, micron flowers begin to gather to form the final zinc oxide micron spherical structure.(3) The zinc oxide flower structure has been prepared by microwave method, the impact of microwave irradiation time and the ratio of the NaOH volume to ZnC12volume on samples have been studied. SEM and XRD show the sample crystalline zinc oxide is a hexagonal system. One-minute microwave radiation leads to crystalline samples with less obvious flower-like structure; when the reaction lasts for3min, a clear flower-like structure of the nano-zinc oxide can be seen; however, when the reaction lasts for5min, a Flower-like structure of ZnO can not be formed. When the ratio of the NaOH volume to the ZnC12volume stands atl:1, the morphology of the sample is a cone structure; when NaOH-ZnCl2volume ratio changes to2:1, the sample morphology is close to the dense accumulation of crystalline and even much closer to the rod-like structure of the Quartet.(4) Referring to the previous research work on this subject, a highly-oriented ZnO nanorod array has been prepared by low-temperature hydrothermal method. Zinc oxide seed layer has been introduced as growth units in the ITO conductive glass to grow zinc oxide nanostructures in a low-temperature hydrothermal environment. The samples are characterized by SEM and XRD, and their optical properties and growth mechanism have been deeply studied. The study finds that zinc oxide crystals are distributed like rod with an average diameter of about150nm, at the top is six square, wich is a typical hexagonal wurtzite structure crystal; zinc oxide crystals are of good optical properties and few defect level, so they can be directly used as fabrication materials. We find that the spin-coated seed layer as the growth units of zinc oxide nanorods directly leads the zinc oxide to grow along the (002) crystal plane; precursor solution concentration and growth time exert great influence on crystallinity and photoluminescent properties. |
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