Effect of nitrogen-vacancy complex defects on the transport properties of single-walled nanotubes were simulated using density functional theory and non-equilibrium Green's functions. It was found that  the defect state in carbon nanotubes becomes spatially localized and developed one half-filled impurity band near the Fermi level for either N-vacancy or N3-vacancy defect. The impurity bands were favorable to the electronic transport of the semiconducting nanotube (8, 0) but weaken that of metallic (4, 4). The studied results showed that the differential conductance of the nanotubes behaves obvious oscillation characteristic.

Effect of Nitrogen-Vacancy Complex Defects on the Electronic Transport of Carbon Nanotube. J.Wei, H.Hu, Z.Wang, H.Zeng, Y.Wei, J.Jia: Applied Physics Letters, 2009, 94[10], 102108