Atomic configurations and energetics of vacancies in hexagonal boron nitride: First-principles total-energy calculations

Abstract

We investigate the energetics and electronic structure of multiatomic vacancies in hexagonal boron nitride ͑h-BN͒ based on the local-density approximation in the density-functional theory. We find that the energetics of vacancies strongly depends not only on the environmental condition of boron and nitrogen chemical potentials but also on electron chemical potentials of these systems. Under nitrogen-and electron-rich conditions, the triangular vacancy comprised of one nitrogen and three boron atoms is a geometrically favorable structure. We also find that the atomic structure of vacancies depends on their charge state. In vacancies with nitrogen edges, the distance between the next-nearest-neighbor nitrogen atoms increases on injection with excess electrons. In contrast, the distance between the next-nearest-neighbor boron atoms decreases for vacancies with boron edges on injection with excess electrons. Our detailed analysis of electronic structures of vacancies unravels the origin of the structural modification of vacancies with regard to their charge state.

Coupling of excitons and defect states in boron-nitride nanostructures

“…[18][19][20][21][22][23][24] The abundance (related to the formation energy) and stability of different defects has been addressed with detailed density-functional theory (DFT) calculations. 20,[25][26][27][28][29] The position of deep levels within the fundamental band gap has been calculated on the DFT level. However, DFT calculation suffer from the well-known underestimation of the band gap.…”

Orientation-controlled growth of hexagonal boron nitride monolayers templated from graphene edges

“…20,21) This preferential formation of triangular defects has been explained theoretically by two mechanisms: knock-on damage 22) and the formation energy of defects. 23,24) The formation energy of defects depends on a variety of factors, such as charge states, edge structures, and edge termination, as predicted by previous theoretical studies. [23][24][25][26][27] It is suggested that the triangular vacancies with nitrogen-terminated zigzag edges can form under nitrogenrich and electron-rich conditions.…”

“…[23][24][25][26][27] It is suggested that the triangular vacancies with nitrogen-terminated zigzag edges can form under nitrogenrich and electron-rich conditions. 23,24) In contrast, the difference in the knock-on damage between boron and nitrogen atoms also explains the formation of triangular defects without any additional mechanisms. Figs.…”

Production of defects in hexagonal boron nitride monolayer under ion irradiation

“…It has been demonstrated however, that the traditional methods for estimating ion irradiation damage like the TRIM approach [10] fail in targets of low dimensionality [11] as detailed account of scattering processes at the atomic level is necessary for correct predictions of the response of nanoscale materials to ion irradiation. Although production of defects in BN nanomaterials under electron irradiation [12][13][14][15][16][17] and defect characteristics [18][19][20][21] have been studied at length, the atomic scale understanding of ion irradiation effects in this material is still lacking.…”