Surface-Enhanced Spectroscopies of a Molecular Monolayer in an All-Dielectric Nanoantenna
Surface-Enhanced Spectroscopies of a Molecular Monolayer in an All-Dielectric Nanoantenna
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DOI：
10.1021/acsphotonics.7b01604
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发表时间：
2018-04-01
期刊：
影响因子：
7
通讯作者：
Maier, Stefan A.
中科院分区：
文献类型：
--
作者：
Cambiasso, Javier;Koenig, Matthias;Maier, Stefan A.
光学纳米天线中存在的损耗衰减通道数量的减少有助于提高发射器的辐射效率。对于靠近金属表面的发射器（例如自组装单层），这些损失会被放大，从而降低荧光率。然而，这种接近会强烈增强拉曼散射。双传感方案应该绕过这个缺点，并且从金属切换到高折射率电介质可能有助于朝这个方向发展。为了证明这一点，我们制造了硅纳米二聚体，并用β-胡萝卜素单层涂覆它们，用于检测同一探针的表面增强拉曼散射和荧光发射。我们获得了多烯链 C-C 键拉伸的表面增强拉曼散射 (SERS) 因子为 1720 +/- 300，表面荧光增强 (SEF) 因子为 470 +/- 90。此外，我们对位于纳米结构表面的不同材料和发射器的理论研究表明，低损耗介电材料为增强高效发射器的响应提供了稳健的结构。这些结果可能对确定性高速率单光子源的发展产生直接影响。
A reduction in the number of loss decay channels present in optical nanoantennas could help enhance an emitter's radiation efficiency. These losses get amplified for emitters in close proximity to metallic surfaces, such as for self-assembled monolayers, reducing the fluorescence rate. However, such a proximity strongly enhances Raman scattering. A dual-sensing scheme should bypass this shortcoming, and switching from metals to high refractive index dielectrics could aid in that direction. In order to show this, we fabricated silicon nanodimers and coated them with a beta-carotenal monolayer for detecting surface-enhanced Raman scattering and fluorescence emission of the same probe. We obtained a surface-enhanced Raman scattering (SERS) factor of 1720 +/- 300 for the C-C bond stretching of the polyene chain and a surface fluorescence enhancement (SEF) factor of 470 +/- 90. Furthermore, our theoretical studies of different materials and emitters located on the surface of nanostructures demonstrate that low-loss dielectric materials provide a robust architecture for enhancing the response of efficient emitters. These results could have a direct impact on the development of deterministic high-rate single-photon sources.