Effect of oxygen doping on electrical properties of small radius (2,1) single-walled carbon nanotubes

We investigated the electrical conductivity of the small radius oxygen-doped (2,1) single-walled carbon nanotubes (SWCNTs) using first-principles density functional theory (DFT). We found that introduction of oxygen does not significantly change the global structure of the SWCNT, and thus the bonding mode of the structure is not remarkably altered. The results show that doping enhances the conductivity of the SWCNT. Oxygen doping increases density of states at the Fermi level, thus the conductivity of the doped SWCNT increases when oxygen is introduced, consistent with experimental observations. These observations were further clarified by comparing band structures of pristine and doped nanotubes.