We present ab initio calculations of transport properties of the multiwalled carbon nanotubes (MWNTs). The tube-electrode contact mode is found to have crucial effects on the transport behavior of MWNTs. It is the outmost-shell contact between MWNT and electrodes that leads to the extensively observed outmost-shell-conducting characteristic in MWNTs transport. In multishell contact mode, however, the outmost shell has no priority to be the route of carrier transport and the quantum conductance is mainly determined by the number of metallic shells which directly contact with electrodes. Our calculations indicate that the dangling bonds usually behave like a carrier scattering site. When the two electrodes are connected to the two different shells of the MWNT, the hopping between adjacent shells would play a decisive role in carrier transport.

• Received 4 August 2005

DOI:https://doi.org/10.1103/PhysRevB.72.155425