Using density-functional theory combined with non-equilibrium Green’s function techniques, studies were made of the electronic transport properties of (7,0)-(8,0), (8,0)-(9,0) and (8,0)-(10,0) single-walled carbon nanotube heterojunctions which contained a pentagon-heptagon (5/7) pair of defects, a pentagon-heptagon (5/7) pair of defects and a pentagon-hexagon-heptagon (5/6/7) topological defect, respectively. The calculations indicated that the 5/6/7 defect had a greater effect upon the electronic transport properties than did the isolated 5/7 defect because there existed three weakly localized states in (8,0)-(10,0) heterojunctions while two existed in (7,0)-(8,0) heterojunctions. There appeared to be a negative differential resistance in the semiconductor-metal (8,0)-(9,0) heterojunction, in the small bias region, due to suppression of the conduction channel.

Quantum Transport Properties of Carbon Nanotube with Topologic Defects. H.Zeng, H.F.Hu, J.W.Wei, W.W.Yang, P.Peng: EPJ Applied Physics, 2008, 43[1], 19-22