Electrochemical Gating Single-Molecule Circuits with Parallel Paths

Authors

Jun-Qing Su, 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Yi-Fan Zhou, 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Ling Tong, 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Ya-Hao Wang, 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Ju-Fang Zheng, 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Jing-Zhe Chen, 2. Department of Physics, Shanghai University, Shanghai 200444, China;
Xiao-Shun Zhou, 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;Follow

Corresponding Author

Xiao-Shun Zhou(xszhou@zjnu.edu.cn)

Abstract

Electrochemical gating has emerged as a feasible and powerful method to tune single-molecule conductance. Herein, we demonstrate that the electron transport through single-molecule circuits with two benzene rings in parallel could be efficiently gated by electrochemistry. The molecular junctions with two parallel paths are fabricated with Au electrodes by STM break junction (STM-BJ) technique. Their conductance value exhibits a 2.82-fold enhancement by the constructive quantum interference compared to single-molecule junctions with single path for electron tunneling. Furthermore, the conductance of para-benzene based molecule could be electrochemically tuned with a modulation ratio of about 333%·V^-1. With the help of DFT calculations, a V-shape spectra of energy-dependent transmission coefficients T(E) around E = E_F leads to the conductance gating behavior. The current work sheds a light on the electrochemical gating of single-molecule circuits with parallel paths, and offers a new way to design molecular materials for a high-performance molecular device.

Graphical Abstract

Keywords

molecular junctions, electrochemical gating, molecular structure, ECSTM-BJ, constructive quantum interference

DOI Link

https://doi.org/10.13208/j.electrochem.201243

Publication Date

2021-04-28

Online Available Date

2021-02-18

Revised Date

2021-02-11

Received Date

2021-01-13

Recommended Citation

Jun-Qing Su, Yi-Fan Zhou, Ling Tong, Ya-Hao Wang, Ju-Fang Zheng, Jing-Zhe Chen, Xiao-Shun Zhou. Electrochemical Gating Single-Molecule Circuits with Parallel Paths[J]. Journal of Electrochemistry, 2021 , 27(2): 195-201.
DOI:

Electrochemical gating has emerged as a feasible and powerful method to tune single-molecule conductance. Herein, we demonstrate that the electron transport through single-molecule circuits with two benzene rings in parallel could be efficiently gated by electrochemistry. The molecular junctions with two parallel paths are fabricated with Au electrodes by STM break junction (STM-BJ) technique. Their conductance value exhibits a 2.82-fold enhancement by the constructive quantum interference compared to single-molecule junctions with single path for electron tunneling. Furthermore, the conductance of para-benzene based molecule could be electrochemically tuned with a modulation ratio of about 333%·V^-1. With the help of DFT calculations, a V-shape spectra of energy-dependent transmission coefficients T(E) around E = E_F leads to the conductance gating behavior. The current work sheds a light on the electrochemical gating of single-molecule circuits with parallel paths, and offers a new way to design molecular materials for a high-performance molecular device.