First-principles study of optical properties of monolayer h-BN and its defect structures under equibiaxial strain

The electronic structure and optical properties of monolayer h-BN were investigated using first-principles calculations. Intrinsic monolayer h-BN is a wide-bandgap semiconductor. When the monolayer h-BN has B defects, the system exhibits metallicity and magnetic properties; when the monolayer h-BN has N defects, the system exhibits semi-metallicity and magnetic. Optical calculations show that the optical parameters of the monolayer h-BN are red-shifted by tensile strain and blue-shifted by compressive strain. The strain synergistic vacancies can significantly modify the monolayer h-BN in the low-energy region, and the B vacancies have a greater effect on the optical parameters of the monolayer h-BN than the N vacancies, which will help the application of monolayer h-BN in visible light region and solar energy region.