A theoretical investigation of defects in a boron nitride monolayer

We have investigated, using first-principles calculations, the energetic stability and structural properties of antisites, vacancies and substitutional carbon defects in a boron nitride monolayer. We have found that the incorporation of a carbon atom substituting for one boron atom, in an N-rich growth condition, or a nitrogen atom, in a B-rich medium, lowers the formation energy, as compared to antisites and vacancy defects. We also verify that defects, inducing an excess of nitrogen or boron, such as N-B and B-N, are more stable in its reverse atmosphere, i.e. N-B is more stable in a B-rich growth medium, while BN is more stable in a N-rich condition. In addition we have found that the formation energy of a C-N, in a N-rich medium, and C-B in a B-rich medium, present formation energies comparable to those of the vacancies, V-N and V-B, respectively.