Length-Dependent Conductance of Molecular Wires and Contact Resistance in Metal-Molecule-Metal Junctions

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Hongmei Liu
  • Nan Wang
  • Jianwei Zhao
  • Yan Guo
  • Xing Yin
  • Freddy Y. C. Boey

Detail(s)

Original languageEnglish
Pages (from-to)1416-1424
Journal / PublicationChemPhysChem
Volume9
Issue number10
Online published2 Jun 2008
Publication statusPublished - 14 Jul 2008
Externally publishedYes

Abstract

Molecular wires are covalently bonded to gold electrodes - to form metal-molecule-metal junctions - by functionalizing each end with a -SH group. The conductance of a wide variety of molecular junctions is studied theoretically by using first-principles density functional theory (DFT) combined with the nonequilibrium Green's function (NEGF) formalism. Based on the chain-length-dependent conductance of the series of molecular wires. the attenuation factor β is obtained and compared with the experimental data. The β value is quantitatively correlated to the molecular HOMO-LUMO gap. Coupling between the metallic electrode and the molecular bridge plays an important role in electron transport. A contact resistance of 6.0±2.0 KΩ is obtained by extrapolating the molecular-bridge length to zero. This value is of the same magnitude as the quantum resistance. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.

Research Area(s)

  • Density functional calculations, Electron transport, Energy gap, Molecular devices, Tunneling attenuation factor

Citation Format(s)

Length-Dependent Conductance of Molecular Wires and Contact Resistance in Metal-Molecule-Metal Junctions. / Liu, Hongmei; Wang, Nan; Zhao, Jianwei; Guo, Yan; Yin, Xing; Boey, Freddy Y. C.; Zhang, Hua.

In: ChemPhysChem, Vol. 9, No. 10, 14.07.2008, p. 1416-1424.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review