基于金属纳米结构非局域与尺寸效应的表面等离激元特性研究

Surface Plasmons Based on Nonlocal and Size-Dependent Effects of Metallic Nanoparticles

结合流体动力学介电模型以及尺寸依赖介电模型,提出了一种可用于描述金属纳米结构中表面等离激元非局域和尺寸效应的介电理论模型。利用不同介质模型对半径为1~100nm的银纳米球进行电子能量损失特性和光学特性的仿真对比,结果表明该理论模型可在较大的能量范围(1~5eV)和尺寸范围(2~200nm)内,兼容有效地反映出局域、非局域、尺寸、甚至是类量子尺寸等效应对金属纳米结构表面等离激元特性的影响作用。同时,研究结果还有助于理解表面等离激元在纳米尺度上的共振模式、能量分布机理和动态演化机制,为等离激元器件的开发设计提供了参考。

Herein,based on the hydrodynamic Drude model and two size-corrective terms derived from the sizedependent dielectric function,a simplified dielectric theoretical model is proposed to describe the nonlocal and sizedependent effects of surface plasmons in metallic nanostructures.Different dielectric models are used to perform numerical simulation comparisons of the electron energy loss spectroscopy and optical responses for silver spherical nanoparticles with different radii of 1-100nm.Results show that the proposed theoretical model can demonstrate great effectiveness in reflecting the effects of local,nonlocal,size-dependent effects,and even analogous quantumsize responses on the surface plasmon characteristics of metallic nanostructures,energy(1-5eV),and size(2-200nm)ranges.Simultaneously,these results are useful in understanding the resonance mode and energy distribution and dynamic evolution mechanisms of surface plasmons,and provide a reference for the development and design of plasmonic elements on the nanometer scale.