The morphology and electrical conductivity of single-wall carbon nanotube thin films prepared by the Langmuir–Blodgett technique

Thin films containing single-wall carbon nanotubes (SWCNTs) have been prepared using the Langmuir–Blodgett (LB) technique. Atomic force microscopy has been used to investigate the morphology of these films. Films of pure SWCNTs were in the form of a network of interconnected bundles of tubes. The in-plane electrical characteristics of the films were measured at room temperature. Approximately ohmic electrical conductivity was observed at low applied voltages for LB films of pure SWCNTs. High power dissipation was found to lead to a reorganisation of the nanotubes in these ultra-thin films. In contrast, multilayer architectures built up from mixtures of SWCNTs and cadmium arachidate exhibited a current I versus voltage V dependence of the form ln(I/V) ∝ V1/2, indicative of Poole–Frenkel conductivity.