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

[摘要] 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.

[关键词] DFT;First principles;H-BN;Electronic structure;Band gap;Hybrid functional;Article