Tailoring the structural and electronic properties of graphene-like ZnS monolayer using biaxial strain

TL;DR

This study uses first-principles DFT calculations to explore how biaxial strain affects the structure and electronic properties of a graphene-like monolayer of ZnS, revealing strain-induced buckling and band gap modifications.

Contribution

It provides the first detailed analysis of strain effects on ML-ZnS's structural buckling and electronic band gap, highlighting potential for nano-device applications.

Findings

Buckling occurs at compressive strain > 0.92%.

Tensile strain of 2.91% converts the band gap from direct to indirect.

Band gap varies linearly with strain within ±6%.

Abstract

Our First-principles Full-Potential Density Functional Theory (DFT) calculations show that a monolayer of ZnS (ML-ZnS), which is predicted to adopt a graphene-like planar honeycomb structure with a direct band gap, undergoes strain-induced modifications in its structure and band gap when subjected to in-plane homogeneous biaxial strain ($\delta$). ML-ZnS gets buckled for compressive strain greater than 0.92%; the buckling parameter $\Delta$ (= 0.00 \AA\, for planar ML-ZnS) linearly increases with increasing compressive strain ($\Delta = 0.435$ \AA \,at $\delta = - 5.25$%). A tensile strain of 2.91% turns the direct band gap of ML-ZnS into indirect. Within our considered strain values of $|\delta| < 6%$, the band gap shows linearly decreasing (non-linearly increasing as well as decreasing) variation with tensile (compressive) strain. These predictions may be exploited in future for potential applications in strain sensors and other nano-devices such as the nano-electromechanical systems (NEMS).