均匀多角锥状纳米ZnO的制备及发光特性研究

Synthesis and Light Emission Properties of Uniform ZnO Tetrapods

采用热蒸发锌（Zn）粉方法制备出大量均匀的纳米ZnO多角锥状结构,用扫描电子显微镜（SEM）、拉曼光谱（Raman Spectra）和光致发光谱（PL）对样品进行形貌、结构和发光特性分析．结果表明：多角锥状纳米ZnO结晶质量好，角的直径约100—200nm，长度约2～3μm，在486nm处有很强的蓝光发射，在394nm，423nm处有较弱的紫外发射，呈现出优异的蓝光特性．针对其强蓝光发射特性并结合实验条件，对其生长机理和发光机制进行初步探讨．

Uniform ZnO tetrapod nanostructure has been synthesized by thermally evaporating Zn powders. Scanning electron microscopy, Raman Spectra and Photoluminescence were employed to determine the structures, morphology and optical properties of the products. From SEM images it is found the diameters of the tetrapods varied from 100- 200 nm and the lengths were about 2 - 3μm. The Raman spectrum showed that the crystallization of ZnO tetrapods is very high. Under the 325 nm light excitation, a very weak near band-edge UV light emission at 394 nm, 423nm and a very strong blue light emission at 486 nm were observed, which indicated that the ZnO nanorods had excellent blue light properties. The growth mechanism and the luminescence mechanism of the ZnO nanorods were discussed. It is speculated that the strong blue emission at 486 nm is due to high surface states and surface defect states introduced in the growth process occasionally.