Quantitative Interpretation of the Low-Bias Conductance of Au-Mesitylene-Au Molecular Junctions Formed from Mesitylene Monolayers.
The atomic structure and electronic transport properties of Au-mesitylene-Au molecular junctions formed from a mesitylene monolayer without any anchoring groups are investigated by employing the non-equilibrium Green's function formalism combined with density functional theory. The intermolecular and adsorbate-substrate interactions are described by the non-local optB88 van der Waals functional. Two types of Au-mesitylene-Au molecular junctions are constructed, in which either an isolated mesitylene molecule or a mesitylene molecule embedded into a monolayer lying flat on one electrode surface is in contact with an atomic protrusion of the other electrode surface. The calculated low-bias conductance values of these two junctions are both in quantitative agreement with the reported experimental values [S. Afsari, Z. Li, and E. Borguet, Angew. Chem. Int. Ed. 2014, 53, 9771; Angew. Chem. 2014, 126, 9929]. This indicates that the measured conductance is intrinsic at the single-molecule Au-mesitylene-Au junction and that the intermolecular interactions in the mesitylene monolayer have little effect.
Department of Electronics, Peking University, Key Laboratory for the Physics and Chemistry of Nanodevices, No. 5, Yiheyuan Road, Haidian District, Beijing, 100871, China.
Hao
H
Wang
Department of Electronics, Peking University, Key Laboratory for the Physics and Chemistry of Nanodevices, No. 5, Yiheyuan Road, Haidian District, Beijing, 100871, China.
Zhuoling
Z
Jiang
Department of Electronics, Peking University, Key Laboratory for the Physics and Chemistry of Nanodevices, No. 5, Yiheyuan Road, Haidian District, Beijing, 100871, China.|Beida Information Research (BIR), No. 39, Gaoxin Road 6, Binhai Technology Garden, Binhai New District, Tianjin, 300457, China.
Yongfeng
Y
Wang
School of Physics, AMBER and CRANN Institute, Trinity College, College Green, Dublin 2, Ireland.
Stefano
S
Sanvito
Department of Electronics, Peking University, Key Laboratory for the Physics and Chemistry of Nanodevices, No. 5, Yiheyuan Road, Haidian District, Beijing, 100871, China. smhou@pku.edu.cn.|Beida Information Research (BIR), No. 39, Gaoxin Road 6, Binhai Technology Garden, Binhai New District, Tianjin, 300457, China. smhou@pku.edu.cn.
Shimin
S
Hou
density functional theory; molecular junctions; molecule-substrate interaction; non-equilibrium green′s function; scanning tunneling microscopy