Ab initio calculations demonstrated that the energy gap modulation of a chiral carbon nanotube with mono-vacancy defect could be achieved by applying a transverse electric field. The band structure of this defective carbon nanotube, varying due to the external electric field, was distinctly different from those of the perfect nanotube and defective zig-zag nanotube. This variation in band structure depended strongly not only upon the chirality of the nanotube and also upon the applied direction of the transverse electric field. A mechanism was proposed to explain the response of the local energy gap between the valence band maximum state and the local gap state under an external electric field.

Effect of Vacancy Defect on Electrical Properties of Chiral Single-Walled Carbon Nanotube under External Electrical Field. Y.P.Luo, L.G.Tien, C.H.Tsai, M.H.Lee, F.Y.Li: Chinese Physics B, 2011, 20[1], 017302