Surface-enhanced Raman spectroscopy: nonlocal limitations
Surface-enhanced Raman spectroscopy: nonlocal limitations
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DOI：
10.1364/ol.37.002538
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发表时间：
2012-07-01
期刊：
影响因子：
3.6
通讯作者：
Mortensen, N. A.
中科院分区：
文献类型：
--
作者：
Toscano, G.;Raza, S.;Mortensen, N. A.
巨大的场增强和场奇点是通常采用的局部响应框架的自然结果。我们表明，对等离子体响应的更一般的非局部处理导致了对场增强的新的和可能的基本限制，这对我们对表面增强拉曼光谱（SERS）的理解产生了重要影响。电子气体的固有长度尺度用于涂抹假定的场奇点，使SERS增强因子有限，即使对于具有无限尖锐特征的几何形状也是如此。对于银纳米槽结构，用半圆柱体的周期性阵列模拟（半径高达120纳米），我们发现没有超过10个数量级的增强因子（10(10)）。(C) 2012美国光学学会
Giant field enhancement and field singularities are a natural consequence of the commonly employed local-response framework. We show that a more general nonlocal treatment of the plasmonic response leads to new and possibly fundamental limitations on field enhancement with important consequences for our understanding of surface-enhanced Raman spectroscopy (SERS). The intrinsic length scale of the electron gas serves to smear out assumed field singularities, leaving the SERS enhancement factor finite, even for geometries with infinitely sharp features. For silver nanogroove structures, mimicked by periodic arrays of half-cylinders (up to 120 nm in radius), we find no enhancement factors exceeding 10 orders of magnitude (10(10)). (C) 2012 Optical Society of America