Influence of atomic vacancies on the electronic and mechanical properties of two-dimensional AsBiSe 3 monolayers

Using first-principles calculations and ab initio molecular dynamics, we investigate the formation of atomic vacancies in the monolayer AsBiSe₃ and its consecutive effect on electronic and mechanical properties. The calculated formation energies reveal that Se vacancies constitute the most stable defect. The energy barrier for the migration of these vacancies between neighboring atomic sites is 1.50 eV, surpassing the barrier energies for the migration of As (1.19 eV) and Bi (0.76 eV) vacancies, confirming their stability. Regarding mechanical properties, we have systematically investigated the mechanical response of all defect configurations considered in the AsBiSe₃ monolayer. The presence of most-stable Se atomic vacancies does not destroy the semiconducting character of AsBiSe₃ but it gives rise to midgap states that could impact the optical and transport characteristics of AsBiSe₃, suggesting avenues for additional research.