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Activated vibrational modes and Fermi resonance in tip-enhanced Raman spectroscopy

Sun, Mengtao; Fang, Yurui; Zhang, Zhenyu and Xu, Hongxing LU (2013) In Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) 87(2).
Abstract
Using p-aminothiophenol (PATP) molecules on a gold substrate and high-vacuum tip-enhanced Raman spectroscopy (HV-TERS), we show that the vibrational spectra of these molecules are distinctly different from those in typical surface-enhanced Raman spectroscopy. Detailed first-principles calculations help to assign the Raman peaks in the TERS measurements as Raman-active and IR-active vibrational modes of dimercaptoazobenzene (DMAB), providing strong spectroscopic evidence for the dimerization of PATP molecules to DMAB under the TERS setup. The activation of the IR-active modes is due to enhanced electromagnetic field gradient effects within the gap region of the highly asymmetric tip-surface geometry. Fermi resonances are also observed in... (More)
Using p-aminothiophenol (PATP) molecules on a gold substrate and high-vacuum tip-enhanced Raman spectroscopy (HV-TERS), we show that the vibrational spectra of these molecules are distinctly different from those in typical surface-enhanced Raman spectroscopy. Detailed first-principles calculations help to assign the Raman peaks in the TERS measurements as Raman-active and IR-active vibrational modes of dimercaptoazobenzene (DMAB), providing strong spectroscopic evidence for the dimerization of PATP molecules to DMAB under the TERS setup. The activation of the IR-active modes is due to enhanced electromagnetic field gradient effects within the gap region of the highly asymmetric tip-surface geometry. Fermi resonances are also observed in HV-TERS. These findings help to broaden the versatility of TERS as a promising technique for ultrasensitive molecular spectroscopy. DOI:10.1103/PhysRevE.87.020401 (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)
volume
87
issue
2
publisher
American Physical Society
external identifiers
  • wos:000314879400004
  • scopus:84874231984
ISSN
1539-3755
DOI
10.1103/PhysRevE.87.020401
language
English
LU publication?
yes
id
d7e914a7-87a9-49f0-b32c-1aecd1c00f4f (old id 3577933)
date added to LUP
2013-03-20 13:45:43
date last changed
2019-08-14 01:13:14
@article{d7e914a7-87a9-49f0-b32c-1aecd1c00f4f,
  abstract     = {Using p-aminothiophenol (PATP) molecules on a gold substrate and high-vacuum tip-enhanced Raman spectroscopy (HV-TERS), we show that the vibrational spectra of these molecules are distinctly different from those in typical surface-enhanced Raman spectroscopy. Detailed first-principles calculations help to assign the Raman peaks in the TERS measurements as Raman-active and IR-active vibrational modes of dimercaptoazobenzene (DMAB), providing strong spectroscopic evidence for the dimerization of PATP molecules to DMAB under the TERS setup. The activation of the IR-active modes is due to enhanced electromagnetic field gradient effects within the gap region of the highly asymmetric tip-surface geometry. Fermi resonances are also observed in HV-TERS. These findings help to broaden the versatility of TERS as a promising technique for ultrasensitive molecular spectroscopy. DOI:10.1103/PhysRevE.87.020401},
  articleno    = {020401},
  author       = {Sun, Mengtao and Fang, Yurui and Zhang, Zhenyu and Xu, Hongxing},
  issn         = {1539-3755},
  language     = {eng},
  number       = {2},
  publisher    = {American Physical Society},
  series       = {Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)},
  title        = {Activated vibrational modes and Fermi resonance in tip-enhanced Raman spectroscopy},
  url          = {http://dx.doi.org/10.1103/PhysRevE.87.020401},
  volume       = {87},
  year         = {2013},
}