Electrical Connectivity in Single-Walled Carbon Nanotube Networks

Transport in single-walled carbon nanotubes (SWCNTs) networks is shown to be dominated by resistance at network junctions which scale with the size of the interconnecting bundles. Acid treatment, known to dope individual tubes, actually produces a dramatic reduction in junction resistances, whereas annealing significantly increases this resistance. Measured junction resistances for pristine, acid-treated and annealed SWCNT bundles correlate with conductivities of the corresponding films, in excellent agreement with a model in which junctions control the overall network performance.