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

Abstract

Our first-principles full-potential density functional theory calculations show that a ZnS monolayer (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 (δ). ML-ZnS gets buckled for compressive strain greater than 0.92% ; the buckling parameter Δ(= 0.00 Å for planar ML-ZnS) linearly increases with increasing compressive strain (Δ = 0.435 Å at δ = −5.25%). A tensile strain of 2.91% turns the direct ML-ZnS band gap into indirect. Within our considered strain values of |δ| < 6%, the band gap shows linearly decreasing (non-linearly increasing as well as decreasing) variation with tensile (compressive) strain. These predictions (based on our calculations with two atoms per unit cell) may be exploited in future for potential applications in strain sensors and other nano-devices such as nano-electromechanical systems and nano-optomechanical systems.