Location-dependent Stone-Wales defect in C/BN heteronanotube: A density functional theory approach

Ab initio pseudopotential density functional calculations of location-dependent Stone-Wales (SW) defect are performed to investigate the electronic and optical characteristics of (10,0) zigzag-edged hybrid Carbone/Boron-Nitride (C/BN) heteronanotubes which recently have been proposed to exhibit promising properties. These heteronanotubes are circumferentially formed from two curled carbon and boron nitride nanoribbons. Here, we report a systematic study on the effective role of SW defect located at different radial positions along the heteronanotube. The calculated band gap of the structures and also SW formation energies reveal that the defects preferentially localize at the very interface of the BN and graphene segments. Moreover, the critical importance of the boundary-oriented SW defect (either BN or graphene edges) is comprehensively studied using optical absorption spectra, electron charge density 2D maps, and bonding configurations of occupied/unoccupied pi orbitals corresponding to the B-C/C-N bonds. Our results provide new insights into the band gap engineering of C/BN heterostructures which are the potential candidate for the future optoelectronic applications.