Electronic structure of graphite-like and rhombohedral boron nitride

Abstract

The electronic spectra of the valence and conduction bands of the hexagonal graphite-like h-BN and rhombohedral r-BN modifications of boron nitride are presented. The electronic structures are calculated by the pseudopotential technique with an auxiliary parameter introduced which takes into account anisotropy of the crystal pseudopotential; the parameter is chosen to ensure agreement with the optical data for h-BN. The electronic structures of both modifications are qualitatively similar but differ slightly (up to ∼0.2 eV) with respect to interband energies. Both modifications are indirect-band dielectrics with minimal indirect and direct band gaps of 4.65 and 5.27 eV, respectively, for h-BN amd 4.8 and 5.5 eV for r-BN. The anisotropy of the electronic structure and its possible alterations on intercalation of the BN lattice with carbon are discussed.