Department of Physics, Xiamen University , Xiamen 361005, China.
State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen 361005, China.
ACS Nano. 2016 Jan 26;10(1):581-7. doi: 10.1021/acsnano.5b05605. Epub 2015 Nov 25.
The precise control over the locations of hot spots in a nanostructured ensemble is of great importance in plasmon-enhanced spectroscopy, chemical sensing, and super-resolution optical imaging. However, for multiparticle configurations over metal films that involve localized and propagating surface plasmon modes, the locations of hot spots are difficult to predict due to complex plasmon competition and synergistic effects. In this work, theoretical simulations based on multiparticle-film configurations predict that the locations of hot spots can be efficiently controlled in the particle-particle gaps, the particle-film junctions, or in both, by suppressing or promoting specific plasmonic coupling effects in specific wavelength ranges. These findings offer an avenue to obtain strong Raman signals from molecules situated on single crystal surfaces and simultaneously avoid signal interference from particle-particle gaps.
在等离子体增强光谱学、化学传感和超分辨率光学成像中，精确控制纳米结构组件中热点的位置非常重要。然而，对于涉及局域和传播表面等离激元模式的金属膜上多粒子结构，由于复杂的等离激元竞争和协同效应，热点的位置难以预测。在这项工作中，基于多粒子-薄膜结构的理论模拟预测，通过在特定波长范围内抑制或促进特定的等离子体耦合效应，可以有效地在粒子-粒子间隙、粒子-薄膜交界处或两者同时控制热点的位置。这些发现为从位于单晶表面的分子获得强拉曼信号提供了一种途径，同时避免了来自粒子-粒子间隙的信号干扰。
