Analogous Atomic and Electronic Properties between V N and

We investigate defect properties in hexagonal boron nitride (hBN) which is attracting much attention as a single photon emitter. Using first-principles calculations, we find that nitrogen-vacancy defect $\left(V_N\right)$ has a lower energy structure in $C_{1h}$ symmetry in 1− charge state than the previously known $D_{3h}$ symmetry structure. Noting that carbon has one more valence electron than boron species, our finding naturally points to the correspondence between $V_N$ and $V_N{C}_B$ defects with one charge state difference between them, which is indeed confirmed by the similarity of atomic symmetries, density of states, and excitation energies. Since $V_N{C}_B$ is considered as a promising candidate for the source of single photon emission, our study suggests $V_N$ as another important candidate worth attention, with its simpler form without the incorporation of foreign elements into the host material.