Pyridine-Ag20 cluster: A model system for studying surface-enhanced Raman scattering

Linlin Zhao, Lasse Jensen, George C. Schatz

Research output: Contribution to journalArticle

384 Citations (Scopus)

Abstract

This work presents a detailed analysis of enhanced Raman scattering of the pyridine-Ag20 model system using time-dependent density functional theory. A consistent treatment of both the chemical and electromagnetic enhancements (EM) is achieved by employing a recently developed approach based on a short-time approximation for the Raman cross section. A strong dependence of the absolute and relative intensities on the binding site and excitation wavelength is found. The analysis of the Raman scattering cross sections shows the importance of different contributions to the enhancements, including static chemical enhancements (factor of 10), charge-transfer enhancements (10 3), and EM enhancements (105). The largest enhancement found (105-106) is due to the EM mechanism, with a small contribution from the chemical interaction. This suggests that the enhanced Raman scattering due to atomic clusters is comparable to findings on single nanoparticles. A combination of information about the vibrational motion and the local chemical environment provides a simple picture of why certain normal modes are enhanced more than others.

Original languageEnglish
Pages (from-to)2911-2919
Number of pages9
JournalJournal of the American Chemical Society
Volume128
Issue number9
DOIs
Publication statusPublished - Mar 8 2006

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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