Conductivity Enhancement of Transparent 2D Carbon Nanotube Networks Occurs by Resistance Reduction in All Junctions

Transparent conductive networks are important for flexible electronics and solar cells. Often interwire (junction) conductivity is the limiting factor for network conductivity and can be improved by various treatments. The conductivity of individual junctions in a single walled carbon nanotube network was measured by conductive atomic force microscopy before and after exposure to nitric acid. The measurements show that this exposure improves the conductivity of each one of the junctions within the network. Our results suggest that the acid improves the conductivity by p-type charge transfer doping and by surfactant degradation.