Using first-principles total energy methods, systematic calculations were made of the formation energies and transition energy levels of intrinsic and extrinsic defects in cubic boron nitride (c-BN). A mixed k-point sampling approach was used which took account of the band-gap error. It was found that, under B-rich conditions, the boron vacancy (VB) and nitrogen vacancy (VN) acted as the predominant compensating centers for additional dopants while, in the N-rich limit, the boron antisite (NB) became the so-called main acceptor killer. The result was inaccessible if the impact of band-gap correction on the formation energies was ignored. Besides, all the calculated defect levels were too deep to account for the observed n- or p-type conductivity in as-grown samples. Among all the attempted dopants, substitutional Be (BeB) was the desirable acceptor in terms of lower formation energy and energy levels under N-rich conditions. However, n-type c-BN seems difficult to obtain under equilibrium conditions, because of the low solubility of dopants and the abundance of the compensating center VB3−.

First-Principles Study of Native and Extrinsic Point Defects in Cubic Boron Nitride. Y.Gai, G.Tang: Physica Scripta, 2011, 83[4], 045605