项目名称： 胶体晶体自组织生长的物理机制、调控及其应用研究

项目编号： No.10804044

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 詹鹏

作者单位： 南京大学

项目金额： 24万元

中文摘要： 由单分散微球通过自组织形成的胶体晶体，以及由其衍生的微结构材料及其光学性质研究，成为近年来凝聚态光物理和材料物理热点交叉领域之一；高质量胶体晶体对制备新型微、纳周期性结构及新型光电子器件提供了一种非常重要的手段。本项目围绕高质量胶体晶体的生长，研究胶体晶体自组织生长过程以及胶体晶体结构参数的控制技术。结合表面张力与楔形毛细通道的微球自组织技术发展了一种能够真正实现大面积单畴二维胶体晶体的制备方法，克服了现有胶体晶体制备技术中高缺陷率，多畴向等问题。以此高质量二维胶体晶体为衬底结合模板复制，发展了一种形貌可控的金属纳米颗粒有序阵列的制备技术，这种有序阵列是由壁厚可调的金属半球壳、球壳、实心球等纳米颗粒组成，是一类具有特殊形貌结构的准三维表面等离激元晶体，我们研究了这一体系的光学特性，以及该体系对环境折射率变化的敏感性，探索其在化学、生物传感以及表面拉曼增强方面应用的可行性。同时，我们还研究了基于高质量胶体晶体的准三维磁表面等离激元晶体的各向异性磁光效应。另外，在有序金属微纳结构材料表面等离激元特性研究方面我们创新性地对超构材料中磁SP模衍射耦合理论及其光频磁场增强效应进行深入探讨。

中文关键词： 胶体晶体;单畴;模板复制;有序阵列;光学性质

英文摘要： A colloidal crystal self-assembled by monodispersed microspheres as well as the corresponding microstructures derived from it is one of the most active research topics in the field of condensed matter physics, materials science and their interdisciplines due to their rich and unique optical properties. The colloidal crystal with high quality provide an alternative to fabricate new-type periodic nanostructures and devices. In this project, we developed a reliable approach to self-organize colloidal shperes into ordered lattices within a wedge-shaped channel. In this way, we yield large area of single-domain monolayer trangle-lattice colloidal crystals. Also, we make a thorough study on the light transmission properties of these two-dimensional (2D) colloidal crystals. Base on these high quality colloidal crystals, a variety of templating methods for the fabrication metallodielectric materials are developed. We prepared monodisperse metallic colloids with controllable cavity and shape, and their free-standing 2D crystals by a combination of nanosphere lithography, restrictive template, and physical deposition. The morphology of metallic colloids (such as half shell, hollow or solid sphere and elliptical shell) can be tuned by the parameters of depositions. These templated methods provide much flexibility in engineering metal surface from the assembly of the metallic colloids with desirable plasmonic properties. We study the optical properties of these novel quasi-3D plasmonic crystals and present better capabilities of sensing and enhancing surface Raman signal than other plasmonic crystals fabricated by micromachining technology. The boost in sensitivity and enhancement of surface Raman signal is consistent with a substantially suppressed substrate effect associated with 3D nature of the metal films. These findings are analyzed numerically by an approximate surface plasmons analysis. Also for the magnetic metal microsturcture based on a 2D colloidal crystal, strong in-plane anisotropy of the magneto-optical Kerr effect is studied.In addition,we studied theoretically the diffraction coupling of magnetic resonances in metamaterials consisting of metallic microsturcture. A dramatic enhancement of magnetic field in the dielectric spacer was achieved as compared with the purely magnetic resonance. Our study opens a new way to high sensitive and low-cost plasmonic crystals with a wide range of chemical and biological sensing applications.

英文关键词： collidal crystal; single domain; templating duplication; ordered array; optical properties