Flexible Transparent Conducting Films Composed of Photochemically Oxidized Thin Multi-Walled Carbon Nanotubes

Abstract

Flexible, transparent conductive films (TCFs) were fabricated by dip-coating polyethylene terephthalate (PET) films in suspensions of thin multi-walled carbon nanotubes (t-MWNTs). The surface density of t-MWNTs in the coatings applied to the PET films was controlled through the number of coatings. In this study, the number of interconnected bundles of t-MWNTs at intersection points and the coverage of MWNTs on the surface of the PET substrates were evaluated because the performance of t-MWNT-based TCFs is influenced by both the electrical conductance and optical transmittance. The microscopic properties of the films were in excellent agreement with the macroscopic properties that were determined by measuring the electrical conductance and optical transmittance of the films, especially for the TCFs with a small number of coatings. The most crucial factor that governs the characteristics of t-MWNT-based TCFs is the network structure of the t-MWNTs. The optimum structure should provide the largest number of intersection points with the smallest number of coatings.