Tuning the Dipolar Plasmon Hybridization of Multishell Metal-Dielectric Nanostructure: Gold Nanosphere in a Gold Nanoshell
Tuning the Dipolar Plasmon Hybridization of Multishell Metal-Dielectric Nanostructure: Gold Nanosphere in a Gold Nanoshell
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DOI：
10.1007/s11468-011-9232-5
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发表时间：
2011-05
期刊：
影响因子：
3
通讯作者：
Zhu Jian;Jian-Jun Li;Jun-wu Zhao
中科院分区：
文献类型：
--
作者：
Zhu Jian;Jian-Jun Li;Jun-wu Zhao
由于内层金球和外层金壳的偶极共振的相互作用，直径小于50 nm的金-介电-金多壳层最多可能存在三种表面等离子体共振(SPR)杂化模式。基于准静态理论的理论计算表明，在吸收光谱中存在SPR谱带的混合和分裂，这使得吸收峰数可以通过改变插入金球的半径、金壳的厚度、中间介电壳层的介电常数或外部环境来调节。在较长波长的两个吸收峰，对应于键壳等离子体和球状等离子体的杂化，通常是强烈的和可调的。与反键壳层等离子体和球状等离子体的对称耦合相对应的短波长吸收峰相对较弱，仅在中壳层介电常数较大、外层介电常数较小、金壳层内径较大、内层金球半径较小的情况下才会出现。此外，通过对局域电场分布的分析，阐明了金-介电-金多壳层纳米结构中等离子体激元杂化的物理来源。
Because of the interaction between dipole resonances of the inner gold sphere and the outer gold shell, gold-dielectric-gold multishells with sub-50 nm diameter may at most have three hybridization modes of surface plasmon resonance (SPR). Theoretical calculations based on quasi-static theory indicate that there are blending and splitting of SPR bands in the absorption spectra, which makes the number of absorption peak tunable by changing the radius of inserted gold sphere, thickness of gold shell, dielectric constant of middle dielectric shell or outer environment. The two absorption peaks at longer wavelength, which correspond to the hybridization from the bonding shell plasmon and the sphere plasmon, are usually intense and well tunable. The absorption peak at shorter wavelength, which corresponds to the symmetric coupling between the anti-bonding shell plasmon and the sphere plasmon, is relative weak and only occurs with large dielectric constant of the middle shell, small dielectric constant of the outer surrounding, large inner radius of the gold shell, and small radius of the inner gold sphere. Furthermore, the physical origin of these plasmon hybridizations in gold-dielectric-gold multishells nanostructure has also been illuminated by analyzing the local electric field distributions.