DFT Study of Hexagonal Boron Nitride Electronic Properties Using Different Types of Exchange Correlation Functionals

Density functional theory (DFT) description of electronic structure and related properties offer significant accuracy with low cost. Unfortunately, most of these calculations based on LDA and GGA Exchange-Correlation (XC) functionals are underestimating the energy band gap. Hybrid functionals seem promising candidates for band gap values enhancement. Hexagonal Boron Nitride (h-BN) is one of the important members of the graphene-like two-dimensional honeycomb structure family which is of great importance both for science and technology. Experimentally, there is convincing evidence for an indirect wide bandgap of about 6 eV. We present in this work a systematic DFT study using different types of Exchange-Correlation (XC) functionals to find out their accuracy to estimate the h-BN band gap along with its band structure and density of states. We tested five types of different functionals to study the band structure and density of states of a single-layer h-BN. Small differences have been noticed regarding band structure and density of state details. Nevertheless, HSE03 deduced the band gap accurately within a 3.4% deviation from the experimental value compared with LDA which showed a 24.4% error.