Electronic structure and optical properties of 2D hexagonal Boron Arsenide

Abstract

Group theory and density functional theory methods are combined to obtain compact and accurate k · p Hamiltonians that describe the bandstructures around the K and Γ points for the 2D material hexagonal boron arsenide (h-BAs) predicted to be an important low-bandgap material for electric, thermoelectric, and piezoelectric properties that supplements the well-studied 2D material hexagonal boron nitride. Hexagonal boron arsenide is a direct bandgap material with band extrema at the K point. The bandgap becomes indirect with a conduction-band minimum at the Γ point subject to a strong electric field or biaxial strain. At even higher electric field strengths (approximately 0.75 VÅ −1 ) or a large strain (14 %) 2D hexagonal boron arsenide becomes metallic. Our k · p models include to leading orders the influence of strain, electric, and magnetic fields. Excellent qualitative and quantitative agreement between density functional theory and k · p predictions are demonstrated for different types of strain and electric fields.

Effects of Electric Field and External Magnetic Field on the Electronic and Thermoelectric Properties of the h-BAs Monolayer and Bilayer: Tight-Binding Approach

“…Mathias et al examined the electronic structure and optical properties of the h-BAs monolayer by k.p theory, and DFT. 33 They calculated the band gap which obtained 0.74 eV and also showed that the optical properties were adjustable by applying an electric field and strain. 29 In this study, we investigate the thermoelectric and electronic properties of the h-BAs monolayer and bilayer using the tight binding model and the Green function approach.…”