对称性破缺的金纳米球核/球壳结构表面等离子共振特性研究

项目名称： 对称性破缺的金纳米球核/球壳结构表面等离子共振特性研究

项目编号： No.11304164

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 钱钧

作者单位： 南开大学

项目金额： 25万元

中文摘要： 包含对称性破缺的金（Au）纳米球核/球壳（核壳）结构具有局域场增强、Fano共振等特性，是当前国际研究的热点，但对同时包含球核偏心和球壳切壳的核壳结构表面等离子共振（SPR）机理尚不清楚。申请者在前期研究中发现，包含Au核偏心的Au-Silica-Au切壳型结构能够产生入射光偏振调制的Fano共振、基于Fano共振的单（多）波长光开关效应等有价值的特性。在本项目中，我们拟研究该结构SPR频率与颗粒几何参数，入射光偏振等的依赖关系；利用等离子杂化理论和耦合振子模型阐明该结构Fano共振的物理机制；研究入射光偏振等对该结构单（多）波长光开关效应的调控规律；进行切壳型纳米核壳制备，开展几何形貌等对SPR频率调控的实验研究。本项目的研究为认识具有对称性破缺的核壳或其他类似结构的SPR特性提供理论基础，对构建以可调控SPR核壳结构为基础的微型生物传感器，光开关等具有重要意义。

中文关键词： 表面等离子共振；对称性破缺；多层纳米壳；等离子杂化；

英文摘要： Symmetry breaking in gold (Au) nanoshells, which can supply many interesting properties, such as local field enhancement and Fano resonance, is a recent research hotspot. However, the surface plasmon resonance (SPR) mechanism of the nanoshells including both the core offset and the shell excision is not clear. In a previous study, we have found that the Au-Silica-Au multilayer nanoshells including the core offset and the shell excision can produce the Fano resonance that are dependent on the polarization of the incident light and single (multi-) wavelength optical switching based on the Fano resonance. In this project, we study the dependence of the SPR frequencies on the geometry of nanoparticles and on the polarization of the incident light by numerical simulation; and we clarify the mechanism of Fano resonance through the plasmon hybridization theory and coupled oscillators model; then we study the modulation of the single (multi-) wavelength optical switching of the nanoparticles by the polarization of the incident light; furthermore, we experimentally prepare the nanoshells with shell excision，and develop experimental study on the modulation of the SPR frequencies by the geometry of the nanoparticles. Our project can provide the theoretical foundation on understanding the SPR properties of the nanoshells or

英文关键词： surface plasmon resonance；symmetry breaking；multilayer nanoshells；plasmon hybridization；