Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces
CALIFORNIA UNIV BERKELEY DEPT OF ELECTRICAL ENGINEERING
Pagination or Media Count:
Using first-principles theory and experiments, chemical contributions to surface-enhanced Raman spectroscopy for a well-studied organic molecule, benzene thiol, chemisorbed on planar Au111 surfaces are explained and quantified. Density functional theory calculations of the static Raman tensor demonstrate 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 electronvibron coupling, as quantified through a deformation potential. A straightforward and general analysis is introduced to extract chemical enhancement from experiments for specific vibrational modes measured values are in excellent agreement with our calculations.
- Atomic and Molecular Physics and Spectroscopy