Formation of type-I quantum wells in hexagonal boron nitride bilayers with strain-induced Moire superlattice

Abstract Using density functional theory combined with the effective screening medium method, the energetics and electronic properties of hexagonal boron nitride (hBN) bilayers consisting of hBN sheets with and without tensile strain were investigated. The hBN bilayer exhibited unique localized states at its valence and conduction band edges that were characterized by perfectly flat dispersion and were isolated from the bulk dispersive valence and conduction bands of hBN. This localization was ascribed to the interlayer orbital hybridization of N and B atoms between the layers in the AA stacking domain, where the hybridization caused upward and downward shifts of the valence and conduction band edges, respectively. Accordingly, the hBN bilayer with a Moire superlattice induced by asymmetric strain formed type-I quantum wells with a nanometer diameter.