Effects of strain on the stability, electronic, and optical properties of new h-BC₂N: a many-body study

Exploring graphene-like two-dimensional materials with exceptional electro-optical properties is highly appealing for optoelectronic devices. Utilizing the PBE + <i>G</i>₀<i>W</i>₀ + BSE method, the stability and electro-optical properties of a new h-BC₂N monolayer were investigated systematically, as well as the effects of strain. The h-BC₂N monolayer was dynamically stable in a broad range of strain and possessed a moderate indirect bandgap. The indirect characteristics could be tuned to a direct nature at a tensile strain of +4%. The direct bandgap was maintained in the strain range of +4% to +10% and decreased linearly with increasing tensile strain. Moreover, the applied tensile strain on h-BC₂N could significantly change its optical transitions, causing a marked redshift and enhancing optical absorption in the near-infrared light. In addition, the binding energy of an exciton could achieve ∼1 eV under a tensile strain. These findings suggest that the h-BC₂N monolayer could be a promising candidate optoelectronic applications.