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We have combined molecular dynamics simulations with first-principles calculations to study electron transport in a single molecular junction of perylene tetracarboxylic diimide (PTCDI) in aqueous solution under external electric gate fields. It is found that the statistics of the molecular conductance are very sensitive to the strength of the electric field. The statistics of the molecular conductance are strongly associated with the thermal fluctuation of the water molecules around the PTCDI molecule. Our simulations reproduce the experimentally observed three orders of magnitude enhancement of the conductance, as well as the temperature dependent conductance, under the electrochemical gates. The effects of the molecular polarization and the dipole rearrangement of the aqueous solution are also discussed.


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Field Effects on the Statistical Behavior of the Molecular Conductance in a Single Molecular Junction in Aqueous Solution

Show Author's information Hui Cao1,2( )Jing Ma2Yi Luo1
Department of Theoretical ChemistrySchool of BiotechnologyRoyal Institute of TechnologyS-106 91 StockholmSweden
School of Chemistry and Chemical EngineeringInstitute of Theoretical and Computational ChemistryKey Laboratory of Mesoscopic Chemistry of Ministry of Education, Nanjing UniversityNanjing210093China

Abstract

We have combined molecular dynamics simulations with first-principles calculations to study electron transport in a single molecular junction of perylene tetracarboxylic diimide (PTCDI) in aqueous solution under external electric gate fields. It is found that the statistics of the molecular conductance are very sensitive to the strength of the electric field. The statistics of the molecular conductance are strongly associated with the thermal fluctuation of the water molecules around the PTCDI molecule. Our simulations reproduce the experimentally observed three orders of magnitude enhancement of the conductance, as well as the temperature dependent conductance, under the electrochemical gates. The effects of the molecular polarization and the dipole rearrangement of the aqueous solution are also discussed.

Keywords: field effect, Molecular junction, solvent effect, temperature effect, statistical behavior

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Publication history

Received: 18 February 2010
Revised: 21 March 2010
Accepted: 21 March 2010
Published: 01 May 2010
Issue date: May 2010

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© The Author(s) 2010

Acknowledgements

Acknowledgements

This work was supported by the Swedish Research Council (VR), the Swedish National Infrastructure for Computing (SNIC), the Natural Science Foundation of China (No. 20825312), and the Fok Ying Tong Education Foundation (No. 111013).

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This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

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