QUASI-PARTICLE BAND-STRUCTURE AND EXCITON SPECTRUM OF HEXAGONAL BORON-NITRIDE USING 2ND-ORDER MOLLER-PLESSET MANY-BODY PERTURBATION-THEORY

Many‐body perturbation theory up to second‐order in the Møller‐Plesset partitioning has been used to calculate the quasiparticle band structure of hexagonal boron nitride, treated as a periodic two‐dimensional system. It was found that correlation leads to an essential narrowing of the fundamental gap. The exciton spectrum has been calculated using the first order irreducible vertex part with Hartree‐Fock and quasiparticle band structure data. It was found that the exciton binding energy amounts to about 10% of the fundamental gap (for the first singlet excitation). Copyright © 1990 John Wiley & Sons, Inc.