稀土掺杂的核-壳结构纳米材料激光选择激发光谱性质研究

项目名称： 稀土掺杂的核-壳结构纳米材料激光选择激发光谱性质研究

项目编号： No.10874180

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 吕少哲

作者单位： 中国科学院长春光学精密机械与物理研究所

项目金额： 28万元

中文摘要： 稀土掺杂的纳米材料由于其独特的光学性能和潜在的应用价值而受到人们的重视。但一般情况下，纳米材料的发光受到表面效应的影响，因此对纳米材料表面和界面效应的研究和对纳米材料包覆后改善发光的研究，探索纳米尺度下材料的光学性质应该是可应用于新型高效发光器件的发光材料的基础研究内容。我们针对这些问题以稀土掺杂的核-壳型结构和复合纳米材料为主要研究对象,利用激光选择激发测量方法为主并结合SEM,TEM,XRD,XPS等材料的表征手段对所制备的纳米材料进行了分析。我们利用稀土离子作为荧光探针，使用激光选择激发光谱来反映稀土离子在不同格位上的分布；反映靠近纳米颗粒表面的稀土离子的局域环境，其结果表明由于纳米晶表面效应，使之掺杂离子的局域环境变化，这种变化导致激发和发射光谱线宽增加等变化，经过对纳米材料进行修饰后减少了表面缺陷对发光的淬灭使发光增强。从所获得的一些研究结果中可以说明对稀土离子做激光选择激发能作为探测纳米颗粒表面微结构的有效方法。

中文关键词： 稀土；纳米晶；选择激发；核壳；掺杂

英文摘要： The rare earth doped nanomaterials have attracted people's attention as their possess unusual optical properties and potential application values.In the ordinary circumstances, the nanomaterial's luminescence properties will be affected by the surface effect, therefore it has been basic research content for new luminescence materials that may be applied in the highly effective luminescence component to study the nanomaterial's surface and interfacial effectes, the improving luminescence property after the wrapped nanomaterials, and explore the nanometer scale material optical properties. In view of these questions we take the rare earth doping nucleus - shell structure and the compound nanomaterials as the main research objects.We make primarily use of the laser selective excitation method and SEM,TEM,XRD and XPS techniques to analyse and character the samples prepared. The rare earth ions are used as the fluorescence probe in laser choice excitation spectra to reflects the rare earth ion distribution in different lattice site and nearness nanoparticle surface rare earth ion local environment. The results indicate that the nanometer crystal surface effects can cause doped rare earth ion local environment variation. The local environment variation can make the stimulation and emission spectrum lines widen. Modifying the nanomaterials to reduce the surface defects that could make luminescence quench enhances the luminescence intensity. So the laser choice excitation method that the rare earth ions are used as the fluorescence probe is an effective method to survey nanoparticle surface microstructure.

英文关键词： rare earth;nanocrystal;selective excitation;core-shell;doping