Electrical conductance and breakdown in individual CNx multiwalled nanotubes

Doping of carbon nanotubes with nitrogen during growth strongly modifies their electronic structure through n-type doping. This provides the possibility of producing nanotubes with high conductances, independent of tube chirality. To date, electrical measurements on individual nitrogen-doped multiwalled nanotubes (CNxMWNTs) have reported surprisingly low conductances (similar to 0.01G(0)). Here the authors present high conductance (1.0 +/- 0.3G(0)) measurements at low bias for individual CNx MWNTs. Conductance increases linearly with voltage at a rate of 0.7 +/- 0.2G(0)/V until the threshold for electrical breakdown is reached. Discrete current steps of 20 +/- 10 mu A are then observed. (c) 2006 American Institute of Physics.