Preparation of mechanically aligned carbon nanotube films and their anisotropic transport phenomena

Thin films of aligned carbon nanotubes (CNTs) were prepared by a simple mechanical rubbing from single-walled carbon nanotube (SWNT) slurry, which was synthesized by the catalytic arc discharge. The measured electrical resistivity shows high anisotropy rho(N)/rho(p) ranging from 5 to 15. The annealed samples show a monotonic decrease in the resistivity with increasing temperature. CNTs in the mat act as strong Luttinger liquids with g values ranging from 0.18 to 0.26, similar to an isolated nanotube. We propose that the transport is dominantly governed by the formation of metal-metal crossed junctions of nanotubes in the mat.