First-principles calculations were used to investigate the atomic geometries and formation energies of vacancies (VN, VB) and antisite defects (BN, NB) in the cubic phase. It was found that VN and VB were the most stable defects in p-type and n-type samples, respectively. They also exhibited intrinsic donor (VN) and acceptor (VB) characteristics; which made them good candidates for compensation. The equilibrium geometries exhibited large outward breathing relaxations for both vacancies and for BN, with a slight Jahn-Teller distortion from Td symmetry. An off-center distortion was found for NB, in neutral and negative charge states, and this induced a negative-U behavior.

Atomic Geometry and Energetics of Vacancies and Antisites in Cubic Boron Nitride. W.Orellana, H.Chacham: Applied Physics Letters, 1999, 74[20], 2984-6