arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.06688physics.opticscond-mat.mtrl-sci
收藏

衬底对针尖增强拉曼光谱的影响--频域模拟与石墨烯测量的比较

Impact of Substrate on Tip-enhanced Raman Spectroscopy --- A Comparison of Frequency Domain Simulations and Graphene Measurements

Hudson Miranda, Cassiano Rabelo, Luiz Gustavo Cancado, Thiago L. Vasconcelos, Bruno S. Oliveira, Florian Schulz, Holger Lange, Stephanie Reich, Patryk Kusch, Ado Jorio

备注：
8 pages, 7 figures
发表信息：
Phys. Rev. Research 2, 023408 (2020)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

尖端增强拉曼光谱（TERS）在环境条件下的测量已经达到纳米空间分辨率，在超高真空下达到亚纳米分辨率。已经获得了超分辨率（超过尖端顶点直径）TERS，主要是在间隙模式配置中，其中导电衬底将电场局部化。在这里，我们提出了实验和理论TERS探索负责光谱增强的场分布。我们使用$40\pm 10 \ \text{nm}$顶点直径的金尖端来测量石墨烯上的TERS，石墨烯是一种空间离域的二维样品，位于不同的基底上：（i）玻璃，（ii）薄层金和（iii）覆盖有$12\ \text{nm}$直径金球的表面，在环境条件下实现了$6\ \text{nm}$分辨率。超分辨率是由于耦合的针尖-样品-衬底系统产生的场配置，表现出非平凡的空间表面分布。场分布和对称性选择规则是不同的非间隙与间隙模式配置。这影响了依赖于拉曼模式对称性和衬底结构的整体增强。

英文摘要：

Tip-enhanced Raman spectroscopy (TERS) has reached nanometer spatial resolution for measurements performed at ambient conditions and sub-nanometer resolution at ultra high vacuum. Super-resolution (beyond the tip apex diameter) TERS has been obtained, mostly in the gap mode configuration, where a conductive substrate localizes the electric fields. Here we present experimental and theoretical TERS to explore the field distribution responsible for spectral enhancement. We use gold tips of $40\pm 10 \ \text{nm}$ apex diameter to measure TERS on graphene, a spatially delocalized two-dimensional sample, sitting on different substrates: (i) glass, (ii) a thin layer of gold and (iii) a surface covered with $12\ \text{nm}$ diameter gold spheres, for which $6\ \text{nm}$ resolution is achieved at ambient conditions. The super-resolution is due to the field configuration resulting from the coupled tip-sample-substrate system, exhibiting a non-trivial spatial surface distribution. The field distribution and the symmetry selection rules are different for non-gap vs. gap mode configurations. This influences the overall enhancement which depends on the Raman mode symmetry and substrate structure.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑