Electronic structure of carbon doped boron nitride nanotubes: a first-principles study

We determine atomic and electronic structures of arm-chair and zigzag boron nitride nanotubes (BN-NTs) of different diameters using first-principles pseudopotential-based density functional theory calculations. We find that the structure of BN-NTs in bundled form is slightly different from that of the isolated BN-NTs, reflecting on the inter-tube interactions. Effects of carbon doping on the electronic structure of (5,5) and (5,0) BN-NTs are determined: carbon substitution either at B-site, being energetically very stable, or at N-site can yield magnetically polarized semiconducting state, whereas carbon substitution at neighbouring B and N sites yields a non-magnetic insulating structure.