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Title: Measurement and understanding of single-molecule break junction rectification caused by asymmetric contacts

Abstract

The contact effects of single-molecule break junctions on rectification behaviors were experimentally explored by a systematic control of anchoring groups of 1,4-disubstituted benzene molecular junctions. Single-molecule conductance and I-V characteristic measurements reveal a strong correlation between rectifying effects and the asymmetry in contacts. Analysis using energy band models and I-V calculations suggested that the rectification behavior is mainly caused by asymmetric coupling strengths at the two contact interfaces. Fitting of the rectification ratio by a modified Simmons model we developed suggests asymmetry in potential drop across the asymmetric anchoring groups as the mechanism of rectifying I-V behavior. This study provides direct experimental evidence and sheds light on the mechanisms of rectification behavior induced simply by contact asymmetry, which serves as an aid to interpret future single-molecule electronic behavior involved with asymmetric contact conformation.

Authors:
; ; ;  [1]
  1. Single Molecule Study Laboratory, College of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, Georgia 30602 (United States)
Publication Date:
OSTI Identifier:
22420006
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ASYMMETRY; BENZENE; CONTROL; ELECTRIC CONDUCTIVITY; INTERFACES; MOLECULES

Citation Formats

Wang, Kun, Zhou, Jianfeng, Hamill, Joseph M., and Xu, Bingqian, E-mail: bxu@engr.uga.edu. Measurement and understanding of single-molecule break junction rectification caused by asymmetric contacts. United States: N. p., 2014. Web. doi:10.1063/1.4891862.
Wang, Kun, Zhou, Jianfeng, Hamill, Joseph M., & Xu, Bingqian, E-mail: bxu@engr.uga.edu. Measurement and understanding of single-molecule break junction rectification caused by asymmetric contacts. United States. doi:10.1063/1.4891862.
Wang, Kun, Zhou, Jianfeng, Hamill, Joseph M., and Xu, Bingqian, E-mail: bxu@engr.uga.edu. Thu . "Measurement and understanding of single-molecule break junction rectification caused by asymmetric contacts". United States. doi:10.1063/1.4891862.
@article{osti_22420006,
title = {Measurement and understanding of single-molecule break junction rectification caused by asymmetric contacts},
author = {Wang, Kun and Zhou, Jianfeng and Hamill, Joseph M. and Xu, Bingqian, E-mail: bxu@engr.uga.edu},
abstractNote = {The contact effects of single-molecule break junctions on rectification behaviors were experimentally explored by a systematic control of anchoring groups of 1,4-disubstituted benzene molecular junctions. Single-molecule conductance and I-V characteristic measurements reveal a strong correlation between rectifying effects and the asymmetry in contacts. Analysis using energy band models and I-V calculations suggested that the rectification behavior is mainly caused by asymmetric coupling strengths at the two contact interfaces. Fitting of the rectification ratio by a modified Simmons model we developed suggests asymmetry in potential drop across the asymmetric anchoring groups as the mechanism of rectifying I-V behavior. This study provides direct experimental evidence and sheds light on the mechanisms of rectification behavior induced simply by contact asymmetry, which serves as an aid to interpret future single-molecule electronic behavior involved with asymmetric contact conformation.},
doi = {10.1063/1.4891862},
journal = {Journal of Chemical Physics},
number = 5,
volume = 141,
place = {United States},
year = {Thu Aug 07 00:00:00 EDT 2014},
month = {Thu Aug 07 00:00:00 EDT 2014}
}