Quantum interference effect in the charge transport through single-molecule benzene dithiol junction at room temperature： An experimental investigation

• Published in: Chinese chemical letters 2018, Vol.29 (1), p.147-150
• Main Authors: Yang, Guogang, Wu, Hao, Wei, Junying, Zheng, Jueting, Chen, Zhaobin, Liu, Junyang, Shi, Jia, Yang, Yang, Hong, Wenjing
• Format: Article
• Language: English
• Subjects: Benzene dithiol; Different connectivity; Mechanically controllable break junction; Quantum interference; Single-molecule conductance
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2017.06.015

The quantum interference effect in the charge transport through single-phenyl molecules received intensive interests from theory but remained as an experimental challenge. In this paper, we investigated the charge transport through single-molecule benzene dithiol （BDT） junction with different connectivities using mechanically controllable break.junction （MCB]） technique. By further improving the mechanical stability and the electronic measuring component of the MCBJ set-up, we obtained the conductance histograms of BDT molecules （BDTs） from the statistical analysis of conductance-distance traces without data selection. By tuning the connectivity, the conductance of BDTs is determined to be 10-12Go, 10-22Go and 10-10Go for pcra, meta, and ortho connectivity, following the trend that ortfio-BDT 〉 para-BDT 〉 meta-BDT. Furthermore, the displacements of the junctions followed the trend that para 〉 meta 〉 ortho, suggesting the charge transport through the molecules via the gold-thiol bond. The different trends between conductance and displacement for different connectivities suggests the presence of destructive quantum interference effect on meta-BDT, which provides the experimental evidence for the quantum interference effect through single-phenyl molecular junctions.