Impact of Strain on Electronic and Optical Properties of MgClBr Monolayer: First-principle Calculation

Abstract

We have introduced a novel halide monolayer, MgClBr, and performed a comprehensive analysis of its structural, and optoelectronics properties using first-principles calculations. The electronic band structure revealed that MgClBr material has a wide “Γ-Γ” direct band gap. The monolayer's dynamic, thermal, and energetic stability is verified through phonon spectra, AIMD calculation, and cohesive energy calculation, respectively. The MgClBr exhibited a 6.08 eV band gap from HSE06 hybrid functional, slightly larger than MgBr2 but smaller than MgCl2 monolayers. The Strain effects on the optoelectronic characteristics are examined. The MgClBr monolayer shows a band gap of 4.23 eV for −10% and 4.30 eV for + 10% strain, remaining stable under these conditions. Notably, the MgClBr monolayer has favourable band-edge alignment for oxidation–reduction processes involved in water splitting at pH zero. Additionally, the monolayer exhibited significant absorption in extreme UV regions, suggesting its potential as a material for optoelectronic nanodevices like UV-emitters and detectors, electrically insulators and non-reflective overlay material.