Department of Chemistry, University of Cambridge, Cambridge, UK.
Nanotechnology. 2013 Jan 25;24(3):035201. doi: 10.1088/0957-4484/24/3/035201. Epub 2012 Dec 21.
In this paper, we study the local-field enhancement in a system of a metallic nanoparticle placed very near to a dielectric substrate. In such systems, intense electric fields are localized in the gap between the particle and the substrate, creating a 'hot-spot' under appropriate excitation conditions. We use finite-element numerical simulations in order to study the field enhancement in this dielectric-metal system. More specifically, we show how the optical properties of the dielectric substrate (n and k) affect the plasmonic field enhancement in the nano-gap. We also analyze the degree of field confinement in the gap and discuss it in the context of utilization for surface-enhanced Raman scattering. We finally show the fields generated by real substrates and compare them to metallic ones.
在本文中，我们研究了置于介质衬底附近的金属纳米粒子系统中的局域场增强。在这种系统中，在适当的激发条件下，强电场被局域在粒子和衬底之间的间隙中，从而产生“热点”。我们使用有限元数值模拟来研究介电金属系统中的场增强。更具体地说，我们展示了介质衬底的光学性质（n 和 k）如何影响纳米间隙中的等离子体场增强。我们还分析了间隙中的场限制程度，并在表面增强拉曼散射的背景下讨论了它。最后，我们展示了实际衬底产生的场，并将其与金属衬底进行了比较。
