复合贵金属纳米颗粒阵列的局域场增强特性及其SERS效应研究

项目名称： 复合贵金属纳米颗粒阵列的局域场增强特性及其SERS效应研究

项目编号： No.11204317

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 周飞

作者单位： 中国科学院合肥物质科学研究院

项目金额： 27万元

中文摘要： 贵金属纳米颗粒阵列SERS衬底由于重复性好、检测信号稳定均匀等优点，在环境检测、食品安全、传感等领域具有重要的应用前景。目前该类衬底通常依靠尖端或狭缝处的近场特性或通过阵列结构的远场相互作用来实现较大的局域场增强，但前者受限于加工精度，而后者的研究中目前仅考虑到单一结构单元组成的阵列，SERS衬底的活性难以得到有效的提高。针对此问题，本项目提出由两种不同的金属纳米颗粒组成的新型复合阵列结构，利用该体系中的二次增强效应有望实现更大的局域场增强。我们将利用数值模拟方法系统的研究复合阵列中电磁相互作用过程，并基于耦合模理论为该体系建立解析/半解析的理论模型；详细探讨阵列参数和结构单元参数对SERS增强效应的影响；优化设计并制备高SERS活性的复合贵金属纳米颗粒阵列衬底。本研究的开展有望揭示复合阵列衬底中SERS增强的物理机制，为高性能SERS衬底的实现提供新的思路，具有重要的科学意义。

中文关键词： 表面等离子体；表面增强拉曼散射；金属微纳结构；局域电场增强；

英文摘要： Surface enhanced Raman scattering (SERS) substrates with periodic nanoparticle array structures have received much attention due to their repeatable and stable performance. The SERS enhancement in nanoparticle arrays usually comes from the near-field enhancement effect of corners and gaps, or from far-field coupling in array structures. However, the near-field enhancement factor is limited by the precision of fabrication, and also, in current far-field coupling researches only uniform arrays are considered, which can not improve the SERS enhancment factor effectively. To solve this problem, we propose a novel hybrid nanoparticle array structure consisting two kinds of nanoparticles, which can enhance the SERS signal in two steps and lead to much larger enhancement. We will theoretically study the interaction between surface plasmon polaritons (SPPs) and localized surface plasmon resonance (LSPR) in the hybrid nanoparticle array by numerical simulations. We will also give an analytical/semi-analytical model based on coupled-mode theory to understand the inside physics mechanism. With this model, we will discuss the relationship between SERS enhancement factor and the parameters of the array (such as the type of array and the periodicity) and the unit cell (such as the shape, size and material). Furtherly, we wil

英文关键词： surface plasmons；surface enhanced Raman scattering；metal micro/nano-structure；local electric field enhancement；