Probing charge states in molecular junctions using Raman spectroscopy

Fatemeh Mirjani, Joseph M. Thijssen, Mark A Ratner

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We examine the Raman spectra of a series of molecules in different charge states and suggest ways of controlling these charge states in charge transport experiments. Our study uses density functional theory (DFT)-based quantum chemical methods. The molecules we study are benzene derivatives, which accommodate transport either through the HOMO or the LUMO (where the HOMO and the LUMO denote the highest occupied molecular orbital and lowest unoccupied molecular orbital, respectively). We have investigated whether observable differences in the Raman spectra will occur upon electron addition or removal. We find substantial frequency shifts upon electron removal or addition. These shifts tend to be uniformly downward in the case of LUMO transport, whereas, for HOMO transport, this unidirectionality is lacking and it is due to the fact that anions are usually less strongly bound than neutrals, whereas removing an electron from a bonding-type orbital usually gives localized modification in bond length and strength.

Original languageEnglish
Pages (from-to)23120-23129
Number of pages10
JournalJournal of Physical Chemistry C
Volume116
Issue number43
DOIs
Publication statusPublished - Nov 1 2012

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Raman spectroscopy
Molecular orbitals
Electrons
Raman scattering
molecular orbitals
Benzene Derivatives
Raman spectra
Molecules
electrons
Bond length
frequency shift
Density functional theory
Anions
Charge transfer
molecules
Benzene
Negative ions
benzene
density functional theory
anions

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Energy(all)

Cite this

Probing charge states in molecular junctions using Raman spectroscopy. / Mirjani, Fatemeh; Thijssen, Joseph M.; Ratner, Mark A.

In: Journal of Physical Chemistry C, Vol. 116, No. 43, 01.11.2012, p. 23120-23129.

Research output: Contribution to journalArticle

Mirjani, Fatemeh ; Thijssen, Joseph M. ; Ratner, Mark A. / Probing charge states in molecular junctions using Raman spectroscopy. In: Journal of Physical Chemistry C. 2012 ; Vol. 116, No. 43. pp. 23120-23129.
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