Improved conductivity of carbon nanotube networks by in situ polymerization of a thin skin of conducting polymer.

The overall conductivity of SWNT networks is dominated by the existence of high resistance and tunneling/Schottky barriers at the intertube junctions in the network. Here we report that in situ polymerization of a highly conductive self-doped conducting polymer "skin" around and along single stranded DNA dispersed and functionalized single wall carbon nanotubes can greatly decrease the contact resistance. The polymer skin also acts as "conductive glue" effectively assembling the SWNTs into a conductive network, which decreases the amount of SWNTs needed to reach the high conductive regime of the network. The conductance of the composite network after the percolation threshold can be 2 orders of magnitude higher than the network formed from SWNTs alone.