Unveiling the optical and thermoelectric properties of topological AsO and SbO monolayers from the first principles study

Abstract

This study presents a comprehensive first-principles analysis of the structural, electrical, optical, topological, and thermoelectric characteristics of oxygen-functionalized arsenene and antimonene employing density functional theory (DFT). Incorporating spin orbit coupling (SOC) at the Γ high symmetry point, AsO and SbO exhibit direct band gaps of 82 meV and 110 meV, respectively. The opening of these band gaps enhances their suitability for advanced high-performance nanoelectronic devices. Notably, both materials maintain the Dirac cone-like electronic structure indicating a transition to a topological insulator phase, characterized by the broken spatial inversion symmetry and a nontrivial topological invariant Z₂ = 1. The optical analysis reveals ultraviolet absorption and reflectivity within the infrared and ultraviolet regions. Furthermore, the thermoelectric properties of these monolayers are found to be predominantly isotropic, with high figure of merit (zT) values of 1.26 and 1.84 at 300 K for the AsO and SbO monolayers, respectively, under light electron doping. These findings highlight the exceptional optical and thermoelectric performance of oxygen-functionalized arsenene and antimonene, underscoring their significant promise for future applications in optoelectronic and thermoelectric technologies.