First-principle calculations on the effect of impurities on different stacking of h-BN bilayers

Abstract

The dependence of the stability and the electronic structure of hexagonal boron nitride bilayers (h-BN) on antisites and carbon impurities has been described and investigated for different types of stacking in order to provide the fingerprint of both the stacking order and substitutional single-atom defects, which affect electronic and chemical properties of such bilayered systems. In doing so, we use first-principle calculations based on density functional theory to study the properties of twelve different h-BN bilayers. In what concerns their stability, we demonstrate, by calculating the formation energy, that carbon impurities are usually more stable than antisite defects and that the environment constituents play a fundamental role in the stability. About the electronic structure, we find that, in general, the defects are responsible for introducing discrete states in the band gap region, whereas the stacking order dictates their positioning with respect to the Fermi level. This emphasizes the importance of the stacking order and defect formation in the control of the electronic properties of nanomaterials.