Enhancement of SERS Background through Charge Transfer Resonances on Single Crystal Gold Surfaces of Various Orientations
Enhancement of SERS Background through Charge Transfer Resonances on Single Crystal Gold Surfaces of Various Orientations
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DOI：
10.1021/ja407459t
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发表时间：
2013-11-20
影响因子：
15
通讯作者：
Uosaki, Kohei
中科院分区：
文献类型：
--
作者：
Ikeda, Katsuyoshi;Suzuki, Shuto;Uosaki, Kohei
表面增强拉曼散射（SERS）光谱伴随着宽背景发射，这限制了信噪比的提高。尽管背景辐射的产生与SERS增强密切相关，但背景辐射的化学来源仍然有些神秘。在这项工作中，在原子定义的不同取向的单晶金表面上系统地测量了有机单层的SERS光谱，具体定义了金属分子的化学相互作用。在明确定义的表面上使用球平面型等离子体纳米隙结构使我们能够评估电荷转移共振对SERS增强的贡献。本研究结果不仅揭示了金属分子界面处的电荷转移共振增加了等离子体介导的宽带发射强度，而且为我们提供了关于金属分子界面电子结构的一致观点。
Surface-enhanced Raman scattering (SERS) spectra are accompanied by broad background emission, which limits improvements in the signal-to-noise ratio. Despite the close correlation between the background generation and the SERS enhancement, the chemical origin of the background emission has remained somewhat mysterious. In this work, SERS spectra of organic monolayers are systematically measured on an atomically defined single crystalline gold surface of various orientations, which specifically define metal molecule chemical interactions. The use of sphere plane type plasmonic nanogap structures on a well-defined surface enables us to evaluate the contribution of charge transfer resonances to SERS enhancement. The present results not only reveal that charge transfer resonance at metal molecule interfaces increases the intensity of plasmon-mediated broadband emission but also provide us a consistent view about electronic structures of metal molecule interfaces.