Two-dimensional III-nitrides: A comprehensive DFT and thermodynamics studies

Abstract

We used DFT simulations for a comprehensive investigation of the stability, corrected electronic band gap, thermodynamic properties and bonding nature of the 2D III-nitrides. The geometry relaxation indicates that all the structures are stable, verified by phonon and molecular dynamics (MD) simulations. The phonon plot shows that all the vibrations are real and there is no imaginary vibration observed. The MD simulations at 500 K for the period of 1ps signify stable structures without any structural distortion. The AIM analysis demonstrates that the electron density, Laplacian and energy density values for X–N (X = B, Al, Ga and In) bonds are in the range of 0.10–0.185 au, 0.36–0.64 au and −0.029 to −0.16 au, which evidenced the partial ionic bonding nature of III-nitrides. The Hirshfeld density analysis shows that significant charge transfer occurred between the X and N atoms. The band gap study performed by HSE06, shows that the BN, AlN, GaN and InN have a band gap value of 5.65, 4.9, 3.45 and 2.0 eV, which are in good agreement with the experimental values compared to other reported theoretical results. This study would be helpful for scientists in the future exploration of 2D III-nitrides for energy, catalysis, optics applications.