▎ 摘　　要

Present work reports the modifications of band structure and density of states of graphene nanosheet by substitutional co-doping of boron (B) and nitrogen (N) in the pristine graphene system. Using ab-initio density functional theory (DFT) we show that the doping position plays an important key role to determine the band-gap in the graphene system. Co-doping of B and N at different sub-lattice positions in the planar graphene structure results different modifications in the band structure and density of states (DOS). Particular choice of sub-lattice doping position of B and N yields a finite value of band gap. (C) 2013 Elsevier B.V. All rights reserved.