| Summary: | 碩士 === 國立成功大學 === 材料科學及工程學系碩博士班 === 96 === A two-step process was developed to grow well-aligned ZnO nanowires on the glass substrate, which induced the pre-deposition of ZnO nanocrystals used as seeds for producing well-aligned, wurtzite ZnO nanowires arrays with spin coating and the arrayed ZnO nanowires. Those were synthesized by low-temperature chemical solution method. Aqueous solution of zinc nitrate hydrate and methenamine were used in this research. Zn(OH)2 would be supersaturated, and ZnO nanocrystals would be precipitated and grown on seed layer. In this research, we study the effect of the different kind of the seed layer synthesized by sol-gel method on the synthesis of aligned ZnO nanowires. Investigations were carried out to probe how the diameter, length, and number density of ZnO nanowires varied and the correlation between quality of ZnO nanowires and the different kinds of seed layers. And we investigated the concentration, temperature, growing time, and pH value of growing bath in order to synthesize the ZnO nanowires with high aspect ratio. We also probed into how the ZnO nanowires grew from ZnO films. Atomic force microscope (AFM) and field-emission scanning electron microscope (FESEM) were used to examine the morphology of the nanowires. The microstructure was investigated by glazing incident X-ray diffraction and high resolution transmission electron microscopy. The property of luminescence was measured by Photoluminescence (PL). The average diameter of nanowires increased with the grain size of the seed layer. The number density of nanowires was related to the roughness, the [0002] preferred orientation, and the grain size of the seed layer. The single crystal ZnO nanowires grew epitaxially from the polycrystalline seed layer directly. In addition, the ZnO nanowires grew on the seed layer fabricated with the precursor with polymer having higher alignment and number density. This study showed that we can get ZnO nanowires with higher aspect ratio and distribution-well diameter in the chemical solution with the concentration ranged from 20mM to 30mM, at temperature about 90℃, and the growing time range from 3hr to 5hr.
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