Electronic structure of graphite-like and rhombohedral boron nitride

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.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 27–32, February, 1992.