Coulomb Repulsion Effect in Two-electron Non-adiabatic Tunneling through a One-level redox Molecule

Igor M. Medvedev, Alexander M. Kuznetsov, Jens Ulstrup

Research output: Contribution to journalJournal articleResearchpeer-review

275 Downloads (Pure)

Abstract

We investigated Coulomb repulsion effects in nonadiabatic (diabatic) two-electron tunneling through a redox molecule with a single electronic level in a symmetric electrochemical contact under ambient conditions, i.e., room temperature and condensed matter environment. The electrochemical contact is representative of electrochemical scanning tunneling microscopy or a pair of electrochemical nanoscale electrodes. The two-electron transfer molecular system also represents redox molecules with three electrochemically accessible oxidation states, rather than only two states such as comprehensively studied. It is shown that depending on the effective Coulomb repulsion energy, the current/overpotential relation at fixed bias voltage shows two narrow (~kBT) peaks in the limit of strong electron-phonon coupling to the solvent environment. The system also displays current/bias voltage rectification. The differential conductance/bias voltage correlation can have up to four peaks even for a single-level redox molecule. The peak position, height, and width are determined by the oxidized and reduced states of both the ionization and affinity levels of the molecule and depend crucially on the Debye screening of the electric field in the tunneling gap. ©2009 American Institute of Physics
Original languageEnglish
JournalJournal of Chemical Physics
Volume131
Issue number16
Pages (from-to)164703
ISSN0021-9606
DOIs
Publication statusPublished - 2009

Bibliographical note

Copyright (2009) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

Keywords

  • INTERFACIAL ELECTRON-TRANSFER
  • TRANSPORT
  • STATE
  • ASSEMBLIES
  • SINGLE-MOLECULE
  • MICROSCOPY
  • TRANSITION-METAL-COMPLEXES
  • JUNCTIONS
  • NITRITE REDUCTASE
  • AU(111) ELECTRODES

Fingerprint Dive into the research topics of 'Coulomb Repulsion Effect in Two-electron Non-adiabatic Tunneling through a One-level redox Molecule'. Together they form a unique fingerprint.

Cite this