金属-半导体复合纳米结构的光学性质研究

项目名称： 金属-半导体复合纳米结构的光学性质研究

项目编号： No.10874020

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： 张伟

作者单位： 北京应用物理与计算数学研究所

项目金额： 40万元

中文摘要： 本项目研究金属和半导体纳米子体系（特别是金属纳米颗粒和半导体量子点）所组成的复合纳米结构的光学性质。考察金属纳米颗粒的基本激发元(等离激元)与半导体量子点的基本激发元(激子)以及光场的相互作用；研究一类新型的准粒子(杂化激子)的性质；讨论由等离共振引起的局域强场和Forster能量传递的竞争效应对量子点光学性质的影响与调控；特别注重激子的离散态和等离激元的准连续态间的相干效应（Fano效应），以及局域强场所导致的非线性光学效应。发展基于密度矩阵和多极展开的理论方法并用来研究这类多种激发元并存、多种机制竞争的复合纳米体系的光学性质，如光吸收、瑞利散射、光致发光谱等，解释已有实验结果，预言新效应，并提出新功能纳米器件设计原理。

中文关键词： 复合纳米结构；金属纳米颗粒；半导体量子点；等离共振；杂化激子

英文摘要： This project studies the optical properties of hybrid nanostructure composed of metal and semiconductor subsystem (in particular, metal nanoparticle and semiconductor quantum dot). We consider the interaction among optical field, the elementary excitation of metal nanoparticle (plasmon), and the elementary excitation of semiconductor quantum dot (exciton). We study the properties of a new type of quasiparticle (hybrid exciton). We address the competition between local strong field (due to plasmon resonance) and the Forster energy transfer, and its effect on the optical properties of semiconductor quantum dot, paying special attention to the interference effect between the discrete states of exciton and semicontinuous states of plasmon (Fano effect), as well as the nonlinear optical effects due to the strong local field. Based on density matrix theory and multipole expansion method, we develop a theoretical approach to study the optical properties (for instance the optical absorption, Rayleigh scattering, photoluminescence, etc) of this type of hybrid nanostructure with several elementary excitations, and competition among several mechanism involved. We explain available experiment results, predict new effects and propose the design principle of new functional nanodevices.

英文关键词： Hybrid nanostructure; metal nanoparticle; semiconductor quantum dot; plasmon resonance; hybrid exciton