C-BN single-walled nanotubes from hybrid connection of BN/C nanoribbons: prediction by ab initio density functional calculations.

We demonstrated for the first time by ab initio density functional calculation and molecular dynamics simulation that C(0.5)(BN)(0.5) armchair single-walled nanotubes (NT) are gapless semiconductors and can be spontaneously formed via the hybrid connection of graphene/BN Nanoribbons (GNR/BNNR) at room temperature. The direct synthesis of armchair C(0.5)(BN)(0.5) via the hybrid connection of GNR/BNNR is predicted to be both thermodynamically and dynamically stable. Such novel armchair C(0.5)(BN)(0.5) NTs possess enhanced conductance as that observed in GNRs. Additionally, the zigzag C(0.5)(BN)(0.5) SWNTs are narrow band gap semiconductors, which may have potential application for light emission. In light of recent experimental progress and the enhanced degree of control in the synthesis of GNRs and BNNR, our results highlight an interesting avenue for synthesizing a novel specific type of C(0.5)(BN)(0.5) nanotube (gapless or narrow direct gap semiconductor), with potentially important applications in BNC-based nanodevices.