Theoretical studies on the near field properties of non-concentric core–shell nanoparticle dimers
Theoretical studies on the near field properties of non-concentric core–shell nanoparticle dimers
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DOI：
10.1016/j.optcom.2010.03.033
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发表时间：
2010-07
影响因子：
2.4
通讯作者：
Binfeng Yun;Zhuyuan Wang;Guohua Hu;Yiping Cui
中科院分区：
文献类型：
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作者：
Binfeng Yun;Zhuyuan Wang;Guohua Hu;Yiping Cui
同心核壳纳米颗粒二聚体在其连接处具有增强电场的“热点”，可用于表面增强拉曼光谱分析。这里通过引入介电核和金属壳之间的转变提出了非同心核壳纳米颗粒二聚体。利用三维时域有限差分法，详细分析了核壳纳米粒子二聚体受非同心位移、二聚体分离、激发波长和偏振影响的等离激元共振和近场特性。结果表明，非同心核壳纳米粒子二聚体的局部近场比同心核壳纳米粒子二聚体的局部近场增强得多。此外，二聚体的等离激元共振波长可以通过核和壳之间的非同心位移来有效调节。所提出的纳米结构在各种近场应用中具有巨大的潜力。
The concentric core–shell nanoparticle dimers have “hot spots” with enhanced electric fields in their junctions, which can be used in the surface enhanced Raman spectra analysis. Here the non-concentric core–shell nanoparticle dimers are proposed by introducing a shift between the dielectric core and the metal shell. By using the three dimensional finite difference time domain method, the plasmon resonances and the near field properties of the core–shell nanoparticle dimers affected by the non-concentric shift, dimer separation, excitation wavelength and polarization are analyzed in detail. The results show that the local near fields of the non-concentric core–shell nanoparticle dimers can be much more enhanced than those of the concentric ones. Also the plasmon resonance wavelengths of the dimers can be effectively tuned by the non-concentric shifts between the core and shell. The proposed nanostructures can have great potential in various near field applications.