Surface-Enhanced Raman Spectroscopy of Graphene
Surface-Enhanced Raman Spectroscopy of Graphene
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DOI：
10.1021/nn1010842
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发表时间：
2010-10-01
期刊：
影响因子：
17.1
通讯作者：
Ferrari, Andrea C.
中科院分区：
文献类型：
--
作者：
Schedin, Fred;Lidorikis, Elefterios;Ferrari, Andrea C.
表面增强拉曼散射（Sers）利用入射场在金属纳米结构中诱导的表面等离子体激元来显著增加拉曼强度。石墨烯为研究Sers提供了理想的原型二维（2D）测试材料。它的拉曼光谱是众所周知的，石墨烯样品是完全可重复的，高度可控制到原子尺度，并且可以几乎无缺陷。我们报告Sers从石墨烯，通过沉积阵列的Au颗粒的明确定义的尺寸上的石墨烯/SiO2（300 nm）/Si系统。我们在633 nm处检测到显著增强。为了阐明Sers的物理机制，我们发展了一个定量的分析和数值理论。石墨烯的2d性质允许与实验一致的拉曼增强的封闭形式描述。我们发现，这与纳米颗粒的横截面，米氏增强的四次方成比例，并与石墨烯和纳米颗粒中心之间的分离的十次方成反比。一个重要的结果是，金属纳米盘是二维Sers的理想实施例。
Surface-enhanced Raman scattering (SERS) exploits surface plasmons induced by the incident field in metallic nanostructures to significantly increase the Raman intensity. Graphene provides the ideal prototype two-dimensional (2d) test material to investigate SERS. Its Raman spectrum is well-known, graphene samples are entirely reproducible, height controllable down to the atomic scale, and can be made virtually defect-free. We report SERS from graphene, by depositing arrays of Au particles of well-defined dimensions on a graphene/SiO2 (300 nm)/Si system. We detect significant enhancements at 633 nm. To elucidate the physics of SERS, we develop a quantitative analytical and numerical theory. The 2d nature of graphene allows for a closed-form description of the Raman enhancement, in agreement with experiments. We show that this scales with the nanoparticle cross section, the fourth power of the Mie enhancement, and is inversely proportional to the tenth power of the separation between graphene and the center of the nanoparticle. One important consequence is that metallic nanodisks are an ideal embodiment for SERS in 2d.