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arXiv · 1011.1873

Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces

A. T. Zayak·Y. S. Hu·H. Choo·J. Bokor·S. Cabrini·P. J. Schuck·J. B. Neaton
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Abstract

Using a combination of first-principles theory and experiments, we provide a quantitative explanation for chemical contributions to surface-enhanced Raman spectroscopy for a well-studied organic molecule, benzene thiol, chemisorbed on planar Au(111) surfaces. With density functional theory calculations of the static Raman tensor, we demonstrate and quantify a strong mode-dependent modification of benzene thiol Raman spectra by Au substrates. Raman active modes with the largest enhancements result from stronger contributions from Au to their electron-vibron coupling, as quantified through a deformation potential, a well-defined property of each vibrational mode. A straightforward and general analysis is introduced that allows extraction of chemical enhancement from experiments for specific vibrational modes; measured values are in excellent agreement with our calculations.

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A. T. Zayak, Y. S. Hu, H. Choo, J. Bokor, S. Cabrini, P. J. Schuck, J. B. Neaton. 2010-11-08. Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces. https://doi.org/10.1103/physrevlett.106.083003

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