Substrates Matter: Influence of an Adjacent Dielectric on an Individual Plasmonic Nanoparticle
Substrates Matter: Influence of an Adjacent Dielectric on an Individual Plasmonic Nanoparticle
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DOI：
10.1021/nl900945q
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发表时间：
2009-05-01
期刊：
影响因子：
10.8
通讯作者：
Halas, Naomi J.
中科院分区：
文献类型：
--
作者：
Knight, Mark W.;Wu, Yanpeng;Halas, Naomi J.
在单个纳米结构水平上研究金属纳米颗粒的等离子体特性对于我们理解纳米级金属系统至关重要。在这里，我们展示了附近介电基板的存在如何改变金属纳米粒子的等离激元模式的能量。相邻的电介质提升了平行和垂直于基底的偶极子等离子体激元模式的简并性，从而引入强烈依赖于基底介电常数的显着能量分裂。这种能量分裂很容易被误解为异常加宽的等离子体线形状，用于用非偏振光激发单个纳米粒子。
Studying the plasmonic properties of metallic nanoparticles at the individual nanostructure level is critical to our understanding of nanoscale metallic systems. Here we show how the presence of a nearby dielectric substrate modifies the energies of the plasmon modes of a metallic nanoparticle. The adjacent dielectric lifts the degeneracy of the dipole plasmon modes oriented parallel and perpendicular to the substrate, introducing a significant energy splitting that depends strongly on the permittivity of the substrate. This energy splitting can easily be misinterpreted as an anomalously broadened plasmon line shape for excitation of an individual nanoparticle with unpolarized light.