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 B(N) 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.