Single-Atom Control of Single-Molecule van der Waals Junctions with Semimetallic Transition Metal Dichalcogenide Electrodes

Zhixing Lu; Songjun Hou; Rongjian Lin; Jie Shi; Qingqing Wu; Shiqiang Zhao; Luchun Lin; Chun Tang; Yang Yang; Colin J Lambert; Wenjing Hong

doi:10.1021/acs.nanolett.3c01264

Single-Atom Control of Single-Molecule van der Waals Junctions with Semimetallic Transition Metal Dichalcogenide Electrodes

Nano Lett. 2023 Jul 12;23(13):6027-6034. doi: 10.1021/acs.nanolett.3c01264. Epub 2023 Jun 30.

Authors

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, IKKEM, Xiamen University, Xiamen 361005, China.
² Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom.

PMID: 37387588
DOI: 10.1021/acs.nanolett.3c01264

Abstract

Electrodes play an essential role in controlling electrode-molecule coupling. However, conventional metal electrodes require linkers to anchor the molecule. Van der Waals interaction offers a versatile strategy to connect the electrode and molecule without anchor groups. Except for graphene, the potential of other materials as electrodes to fabricate van der Waals molecular junctions remains unexplored. Herein, we utilize semimetallic transition metal dichalcogenides (TMDCs) 1T'-WTe₂ as electrodes to fabricate WTe₂/metalated tetraphenylporphyrin (M-TPP)/WTe₂ junctions via van der Waals interaction. Compared with chemically bonded Au/M-TPP/Au junctions, the conductance of these M-TPP van der Waals molecular junctions is enhanced by ∼736%. More importantly, WTe₂/M-TPP/WTe₂ junctions exhibit the tunable conductance from 10^-3.29 to 10^-4.44 G₀ (1.15 orders of magnitude) via single-atom control, recording the widest tunable range of conductance for M-TPP molecular junctions. Our work demonstrates the potential of two-dimensional TMDCs for constructing highly tunable and conductive molecular devices.

Keywords: break junction; charge transport; single-molecule junction; transition metal dichalcogenides; van der Waals interaction.