Comparative Study of the Conductivity Percolation Behaviour of Nanocomposite Thin Layers Made of Nanoparticulate ITO and Carbon Nanotubes Colloids

The electrical conductivity behaviour of two transparent conducting nanocomposite thin films made of nanoparticulate indium tin oxide (ITO) and carbon multiwall nanotubes (MWNTs) colloids deposited on a polycarbonate substrate was studied. The carbon MWNTs films exhibit a low critical threshold (0.083 vol. %) compared with that of the ITO films (0.19 vol. %). The surface morphology of the films shows stronger aggregation of the carbon MWNTs above the critical threshold. The elctrical conductivity obtained for the ITO films is 526 Sm^-1, which is larger than that obtained for the carbon MWNTs films (65 Sm^-1). The optical properties of ITO films show higher transmission in the visible range with a smaller transmission window than that of the carbon MWNTs. Both coatings show similar mechanical properties against abrasion with a very good adhesion on the plastic substrate.