Strain-dependent modulation of conductivity in single layer transition-metal dichalcogenides

TL;DR

This study investigates how mechanical strain influences the electrical conductivity of monolayer transition-metal dichalcogenides, revealing a strain-induced semiconductor-metal transition that enhances electron transport.

Contribution

It provides the first detailed quantum conductance analysis of strained MoS2 and WS2 monolayers using advanced computational methods, highlighting the strain thresholds for electronic phase transitions.

Findings

Strain causes significant electronic structure changes in TMD monolayers.

A semiconductor-metal transition occurs at approximately 11% elongation.

Strain enhances electron transport in these 2D materials.

Abstract

Quantum conductance calculations on the mechanically deformed monolayers of MoS$_2$ and WS$_2$ were performed using the non-equlibrium Green's functions method combined with the Landauer-B\"{u}ttiker approach for ballistic transport together with the density-functional based tight binding (DFTB) method. Tensile strain and compression causes significant changes in the electronic structure of TMD single layers and eventually the transition semiconductor-metal occurs for elongations as large as ~11% for the 2D-isotropic deformations in the hexagonal structure. This transition enhances the electron transport in otherwise semiconducting materials.