Quantised Conductance - Doped Carbon Nanotubes

[Husina]

As I understand it, carbon nanotube (CNT) exhibits quantised conductance (2e^2/h) because the mean free path length of carbon nanotubes are often longer than the length of the tubes.

If one is to substitutionally dope CNTs (say armchair metallic CNTs) with other atoms of similar size, for example boron or nitrogen, does this mean that no increase in the conductance can be expected from the additional states introduced (as conductance is quantised)?

Alternatively, would the conductance decrease because of reduced mean free path length caused by the doped atoms?

 

[Navin A S]

The answer to this question is not straightforward, as it depends on a number of factors. In general, the introduction of dopants can affect the conductance of CNTs in both positive and negative ways. On the one hand, the presence of dopants can introduce additional states into the nanotube that may enable more efficient conduction. On the other hand, dopants can also reduce the mean free path length of the nanotube, which could ultimately lead to lower conductance. In addition, the type of dopant used and the concentration of dopant can also influence the conductance of the CNT.