Electronic Phase Transformations and Energy Gap Variations in Uniaxial and Biaxial Strained Monolayer VS$_2$ TMDs: A Comprehensive DFT and Beyond-DFT Study

TL;DR

This study investigates how uniaxial and biaxial strains influence the electronic phase transitions and energy gap variations in monolayer VS$_2$ TMDs using advanced DFT and beyond-DFT computational methods.

Contribution

It provides a comprehensive analysis of strain effects on VS$_2$ monolayer's electronic structure, highlighting phase shifts and energy gap tuning under different strain conditions.

Findings

Strains between -5 ext% and +5\text% significantly alter the energy gap.

Uniaxial strain has a stronger impact than biaxial strain.

Compressive strain induces a transition from semiconducting to metallic phase.

Abstract

In the field of 2D materials, transition metal dichalcogenides (TMDs) are gaining attention for electronic applications. Our study delves into the H-phase monolayer VS$_2$ of the TMD family, analyzing its electronic structure and how strain affects its band structure using Density Functional Theory (DFT). Using a variety of computational methods, we provide an in-depth view of the electronic band structure. We find that strains between -5\% and +5\% significantly affect the energy gap, with uniaxial strains having a stronger effect than biaxial strains. Remarkably, compressive strains induce a phase shift from semiconducting to metallic, associated with symmetry breaking and changes in bond length. These findings not only deepen our understanding of the electronic nuances of monolayer VS$_2$ under varying strains but also suggest potential avenues for creating new electronic devices through strain engineering.