Abstract

Research in molecular electronics often in olves the demonstration of devices that are analogous to conventional semiconductor devices, such as transistors and diodes, but it is also possible to perform experiments that have no parallels in conventional electronics. For example, by applying a mechanical force to a molecule bridged between two electrodes, a device known as a molecular junction, it is possible to exploit the interplay between the electrical and mechanical properties of the molecule to control charge transport through the junction. 1,4′2-Benzenedithiol is the most widely studied molecule in molecular electronics 9-18, and it was shown recently that the molecular orbitals can be gated by an applied electric field. Here, we report how the electromechanical properties of a 1,4ĝ€2- benzenedithiol molecular junction change as the junction is stretched and compressed. Counterintuitively, the conductance increases by more than an order of magnitude during stretching, and then decreases again as the junction is compressed. Based on simultaneously recorded current-voltage and conductance-voltage characteristics, and inelastic electron tunnelling spectroscopy, we attribute this finding to a strain-induced shift of the highest occupied molecular orbital towards the Fermi level of the electrodes, leading to a resonant enhancement of the conductance. These results, which are in agreement with the predictions of theoretical models 14-17,19,20, also clarify the origins of the long-standing discrepancy between the calculated and measured conductance values of 1,4′2-benzenedithiol, which often differ by orders of magnitude 21.

Original languageEnglish (US)
Pages (from-to)35-40
Number of pages6
JournalNature Nanotechnology
Volume7
Issue number1
DOIs
StatePublished - Jan 2012

Fingerprint

Molecular orbitals
Molecular electronics
molecular orbitals
alignment
Molecules
molecular electronics
molecules
Electrodes
Electron tunneling
Electric potential
Semiconductor devices
Fermi level
Stretching
Charge transfer
Transistors
Diodes
Electric properties
Electronic equipment
Demonstrations
Electric fields

ASJC Scopus subject areas

  • Bioengineering
  • Biomedical Engineering
  • Materials Science(all)
  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics

Cite this

Mechanically controlled molecular orbital alignment in single molecule junctions. / Bruot, Christopher; Hihath, Joshua; Tao, Nongjian.

In: Nature Nanotechnology, Vol. 7, No. 1, 01.2012, p. 35-40.

Research output: Contribution to journalArticle

Bruot, Christopher ; Hihath, Joshua ; Tao, Nongjian. / Mechanically controlled molecular orbital alignment in single molecule junctions. In: Nature Nanotechnology. 2012 ; Vol. 7, No. 1. pp. 35-40.
@article{a6ac779ca7f84b5f9d936ca6eff51f45,
title = "Mechanically controlled molecular orbital alignment in single molecule junctions",
abstract = "Research in molecular electronics often in olves the demonstration of devices that are analogous to conventional semiconductor devices, such as transistors and diodes, but it is also possible to perform experiments that have no parallels in conventional electronics. For example, by applying a mechanical force to a molecule bridged between two electrodes, a device known as a molecular junction, it is possible to exploit the interplay between the electrical and mechanical properties of the molecule to control charge transport through the junction. 1,4′2-Benzenedithiol is the most widely studied molecule in molecular electronics 9-18, and it was shown recently that the molecular orbitals can be gated by an applied electric field. Here, we report how the electromechanical properties of a 1,4ĝ€2- benzenedithiol molecular junction change as the junction is stretched and compressed. Counterintuitively, the conductance increases by more than an order of magnitude during stretching, and then decreases again as the junction is compressed. Based on simultaneously recorded current-voltage and conductance-voltage characteristics, and inelastic electron tunnelling spectroscopy, we attribute this finding to a strain-induced shift of the highest occupied molecular orbital towards the Fermi level of the electrodes, leading to a resonant enhancement of the conductance. These results, which are in agreement with the predictions of theoretical models 14-17,19,20, also clarify the origins of the long-standing discrepancy between the calculated and measured conductance values of 1,4′2-benzenedithiol, which often differ by orders of magnitude 21.",
author = "Christopher Bruot and Joshua Hihath and Nongjian Tao",
year = "2012",
month = "1",
doi = "10.1038/nnano.2011.212",
language = "English (US)",
volume = "7",
pages = "35--40",
journal = "Nature Nanotechnology",
issn = "1748-3387",
publisher = "Nature Publishing Group",
number = "1",

}

TY - JOUR

T1 - Mechanically controlled molecular orbital alignment in single molecule junctions

AU - Bruot, Christopher

AU - Hihath, Joshua

AU - Tao, Nongjian

PY - 2012/1

Y1 - 2012/1

N2 - Research in molecular electronics often in olves the demonstration of devices that are analogous to conventional semiconductor devices, such as transistors and diodes, but it is also possible to perform experiments that have no parallels in conventional electronics. For example, by applying a mechanical force to a molecule bridged between two electrodes, a device known as a molecular junction, it is possible to exploit the interplay between the electrical and mechanical properties of the molecule to control charge transport through the junction. 1,4′2-Benzenedithiol is the most widely studied molecule in molecular electronics 9-18, and it was shown recently that the molecular orbitals can be gated by an applied electric field. Here, we report how the electromechanical properties of a 1,4ĝ€2- benzenedithiol molecular junction change as the junction is stretched and compressed. Counterintuitively, the conductance increases by more than an order of magnitude during stretching, and then decreases again as the junction is compressed. Based on simultaneously recorded current-voltage and conductance-voltage characteristics, and inelastic electron tunnelling spectroscopy, we attribute this finding to a strain-induced shift of the highest occupied molecular orbital towards the Fermi level of the electrodes, leading to a resonant enhancement of the conductance. These results, which are in agreement with the predictions of theoretical models 14-17,19,20, also clarify the origins of the long-standing discrepancy between the calculated and measured conductance values of 1,4′2-benzenedithiol, which often differ by orders of magnitude 21.

AB - Research in molecular electronics often in olves the demonstration of devices that are analogous to conventional semiconductor devices, such as transistors and diodes, but it is also possible to perform experiments that have no parallels in conventional electronics. For example, by applying a mechanical force to a molecule bridged between two electrodes, a device known as a molecular junction, it is possible to exploit the interplay between the electrical and mechanical properties of the molecule to control charge transport through the junction. 1,4′2-Benzenedithiol is the most widely studied molecule in molecular electronics 9-18, and it was shown recently that the molecular orbitals can be gated by an applied electric field. Here, we report how the electromechanical properties of a 1,4ĝ€2- benzenedithiol molecular junction change as the junction is stretched and compressed. Counterintuitively, the conductance increases by more than an order of magnitude during stretching, and then decreases again as the junction is compressed. Based on simultaneously recorded current-voltage and conductance-voltage characteristics, and inelastic electron tunnelling spectroscopy, we attribute this finding to a strain-induced shift of the highest occupied molecular orbital towards the Fermi level of the electrodes, leading to a resonant enhancement of the conductance. These results, which are in agreement with the predictions of theoretical models 14-17,19,20, also clarify the origins of the long-standing discrepancy between the calculated and measured conductance values of 1,4′2-benzenedithiol, which often differ by orders of magnitude 21.

UR - http://www.scopus.com/inward/record.url?scp=84855267115&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84855267115&partnerID=8YFLogxK

U2 - 10.1038/nnano.2011.212

DO - 10.1038/nnano.2011.212

M3 - Article

C2 - 22138861

AN - SCOPUS:84855267115

VL - 7

SP - 35

EP - 40

JO - Nature Nanotechnology

JF - Nature Nanotechnology

SN - 1748-3387

IS - 1

ER -