First-principles study on atomistic and electronic structures of boron-nitrogen and boron-phosphorous nanoribbons, nanorings, and nanotubes

We computationally study the atomistic and electronic structures of boron-phosphorous (BP) nanoribbons (NRBs), nanorings (NRGs), and nanotubes (NTBs) by comparison with similar boron-nitride (BN) nanostructures. We consider polyacene (PAC)-type NRBs. First-principles calculations demonstrate that BN PAC-type finite NRBs conserve the flatness of the NRB plane whereas BP NRBs result in bendings along the NRB plane. Rolling of an NRB (head to tail) produces an NRG. Accordingly, a specific NRG with a "magic ring number" is produced in the BP system whereas BN-NRGs freely produced various ring numbers as well as cyclacene systems. Stacking of NRGs further produces an NTB whose electronic characteristics are determined by the chiral index. However, the band-edge states of heteroatom NTBs are controlled by the difference in the on-site energies rather than by the chiral index.