Accurate Ground State Electronic and Related Properties of Hexagonal Boron Nitride (h-BN)

Abstract

We present an ab-initio, self – consistent density functional theory (DFT) description of ground state electronic and related properties of hexagonal boron nitride (h-BN). We used a local density approximation (LDA) potential and the linear combination of atomic orbitals (LCAO) formalism. We rigorously implemented the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF). The method ensures a generalized minimization of the energy that is far beyond what can be obtained with self-consistency iterations using a single basis set. The method leads to the ground state of the material, in a verifiable manner, without employing over-complete basis sets. Consequently, our results possess the full, physical content of DFT, as per the second DFT theorem [AIP Advances, 4, 127104 (2014)]. We report the ground state band structure, band gap, total and partial densities of states, and electron and hole effective masses. Our calculated, indirect band gap of 4.37 eV, obtained with room temperature experimental lattice constants of a = 2.504 Å and c = 6.661 Å, is in agreement with the measured value of 4.3 eV. The valence band maximum is slightly to the left of the K point, while the conduction band minimum is at the M point. Our calculated total width of the valence and total and partial densities of states are in agreement with corresponding, experimental findings.