Influence of vacancies on metallic nanotube transport properties

The electronic behavior of metallic carbon nanotubes under the influence of atomistic vacancy defects present in the channel is theoretically investigated using non-equilibrium Green's function method self-consistently coupled with three-dimensional electrostatics. A nearest neighbor tight binding model based on a single p(z) orbital is used for the device Hamiltonian. A single vacancy defect in the channel of a small diameter metallic carbon nanotube can decrease its conductance by a factor of 2. More than one vacancy in the channel can further drastically decrease the conductance. Larger diameter nanotubes suffer less from the presence of vacancy defects. (C) 2007 American Institute of Physics.