非局域效应下金属亚纳米结构表面等离激元近场增强特性的研究

项目名称： 非局域效应下金属亚纳米结构表面等离激元近场增强特性的研究

项目编号： No.61505135

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 刘欣

作者单位： 太原理工大学

项目金额： 20万元

中文摘要： 近年来，随着金属纳米结构制备技术的发展，表面等激元在间隙结构中的激发与应用已经成为研究热点之一。在亚纳米尺度下时，基于自由电子响应的传统局域模型失效，而非局域模型和量子修正模型能对散射光谱做出预测。然而，亚纳米尺度表面等离激元近场增强受限特性的实验探测在尺寸连续可调性和场强增益的有效利用方面受到了限制，且非局域模型的主导空间范围尚未明确。.对此本项目将采用金属探针与覆盖单分子层有机材料的金属薄膜制备耦合纳米结构，与拉曼光谱系统共同构成纳米间隙尺寸可调的尖端增强拉曼光谱系统，从理论和实验上研究三维金属亚纳米间隙结构表面等离激元的激发行为和近场增强受限特性。通过将属亚纳米结构间隙尺寸对散射光谱和近场分布的影响规律的实验结果与理论结果进行比较，希望对两种模型的主导空间范围进行探索，并对表面等离激元应用中常见金属材料的非局域效应进行研究。该项目能够为亚纳米尺度下表面等离激元近场增强的应用提供帮助。

中文关键词： 纳米光子学；表面等离激元；表面增强拉曼散射；金属纳米结构；尖端增强拉曼光谱术

英文摘要： More recently, the excitation and applications of surface plasmon polaritons (SPPs) at sub-nanoscale has been one of the most attractive research field attributed to the rapid development of fabrication techniques for metallic nanostructures. At this scale, the nonlocal model and quantum-corrected model can produces great prediction of the properties of scattering spectra than that would be achieved from classical treatment. However, in the existing literatures of experimentally studying of near-field limitation properties, researchers mainly focused on the resonance shift of scattering, whereas a little experimental works of the suppressed near-field enhancement are limited associated with disadvantages on the aspect of non-continuous adjustable gap size of the nanostructures and non-effective utilization of near-field enhancement. Meanwhile, the dominant spatial scale of the nonlocal model is still unclear..This project proposes to adopt a tip-enhanced Raman spectroscopy (TERS) system composed of Raman spectroscopy system with feedback control and a coupled structure consisting of a nanoscale metallic probe tip and thin metal film coated by polyelectrolytes with monolayers, in between with an adjustable gap size. This system can be utilized to theoretically and experimentally investigate the mechanism of excitation of SPPs and properties of near-field distribution within a sub-nanometer gap between the three-dimensional metallic probe tip-film structures with continuous adjustability. Through the realization of detecting the effect of gap size of the metallic nanostructure on scattering spectroscopy and near-field enhancement, the dominant spatial scales of nonlocal model and quantum-corrected model can be distinguished. The nonlocal effect of other metal materials will also be studied in this project. It is expected that this project can provide basis and help for the applications of SPPs in sub-nanoscale region.

英文关键词： Nanophotonics;Surface plasmon polaritons;Surface-enhanced Raman scattering;Metal nanostructures;Tip-enhanced Raman spectroscopy