Abstract:
First principles calculations have been performed to investigate the ground state properties of freestanding
monolayer hexagonal boronitrene (h-BN). We have considered monolayers that contain
native point defects and their complexes, which form when the point defects bind with the boron
vacancy on the nearest neighbour position. The changes in the electronic structure are analysed to
show the extent of localization of the defect-induced mid-gap states. The variations in formation
energies suggest that defective h-BN monolayers that contain carbon substitutional impurities are
the most stable structures irrespective of the changes in growth conditions. The high energies of
formation of the boron vacancy complexes suggest that they are less stable, and their creation by
ion bombardment would require high energy ions compared to point defects. Using the relative
positions of the derived mid-gap levels for the double vacancy complex, it is shown that the quasi
donor-acceptor pair interpretation of optical transitions is consistent with stimulated transitions
between electron–hole states in boronitrene.
