A Density Functional Theoretical Study on the Charge‐Transfer Enhancement in Surface‐Enhanced Raman Scattering
- 20 November 2018
- journal article
- research article
- Published by Wiley in Chemphyschem
- Vol. 19 (24), 3401-3409
- https://doi.org/10.1002/cphc.201800812
Abstract
The chemical enhancement due to ground‐state charge transfer (GSCT) and photon‐driven charge transfer (PDCT) in SERS has been investigated by density functional theory. Para‐substituted thiophenol derivatives adsorbed on silver and gold surfaces are selected as model systems to evaluate the chemical enhancement factor. By changing the functional groups on thiophenol, we are allowed to modulate the chemical interactions between the thiophenol and the metal cluster in both ground state and charge transfer excited state. Both off‐resonance and pre‐resonance SERS spectra are simulated to calculate the chemical enhancement factors. The GSCT enhancement factor, EFGSCT, shows a roughly liner relationship to (ωTP/ωM‐TP)⁴, where ωTP denotes the HOMO‐LUMO gap of free molecule, and ωM‐TP denotes the energy difference between the HOMO of the molecule and the LUMO of the metal. The PDCT enhancement factor, EFPDCT, is governed by the energy difference between the incident light energy and the excitation energy to the CT excited state. EFPDCT first increases and then decreases with the increase of incident light energy.Keywords
Funding Information
- National Natural Science Foundation of China (21603176)
This publication has 64 references indexed in Scilit:
- Surface-Enhanced Raman Spectroscopy for Bioanalysis: Reliability and ChallengesChemical Reviews, 2018
- Surface‐Enhanced Raman Spectroscopy: Concepts and Chemical ApplicationsAngewandte Chemie International Edition, 2014
- Oberflächenverstärkte Raman‐Spektroskopie: Konzepte und chemische AnwendungenAngewandte Chemie, 2014
- Chemical mapping of a single molecule by plasmon-enhanced Raman scatteringNature, 2013
- Theoretical Studies of Plasmonics using Electronic Structure MethodsChemical Reviews, 2011
- Shell-isolated nanoparticle-enhanced Raman spectroscopyNature, 2010
- Electrochemical surface-enhanced Raman spectroscopy of nanostructuresChemical Society Reviews, 2008
- Electronic structure methods for studying surface-enhanced Raman scatteringChemical Society Reviews, 2008
- Surface-enhanced Raman scatteringChemical Society Reviews, 1998
- Surface-enhanced spectroscopyReviews of Modern Physics, 1985