DFT study of structural, electronic and optical properties of 2D MgO monolayer under bi-axial mechanical strain

TL;DR

This study uses first-principles calculations to analyze how bi-axial mechanical strain affects the structural, electronic, and optical properties of 2D MgO monolayer, revealing its stable semiconducting nature and optical characteristics.

Contribution

It provides the first detailed computational analysis of the strain-dependent properties of 2D MgO monolayer, including electronic structure and optical responses.

Findings

MgO monolayer remains an indirect band gap semiconductor under strain.

Optical properties such as dielectric function and refractive index are characterized.

Maximum refractive index of 2.13 at 3.12 eV energy.

Abstract

The structural, electronic, and dielectric (optical) properties of graphene-like 2D MgO monolayer have been explored through first-principles calculations under bi-axial tensile and compressive mechanical strain within a range of -10% to +10%. Our findings revealed that the pristine MgO monolayer is an indirect band gap semiconducting material and the semiconducting mature of MgO monolayer remains consistent under both compressive and tensile mechanical strain. This nature of MgO is confirmed through partial density of states (PDOS) as well as electronic band structure. PDOS exhibits the contribution of different atomic orbitals in bond formation and nature of bond, while band structure provides insight into electron transitions between energy levels of valance and conduction bands. All optical parameters (dielectric function, reflectivity, energy loss, refractive index, extinction coefficient and absorption) are plotted in an energy range 0-15 eV. Within this energy interval, MgO possesses the highest value of the refractive index (2.13) at 3.12 eV energy. Also, a detailed analysis of changes in the geometrical structure of MgO monolayer is provided.