Transparent conducting antimony-doped tin oxide films containing functionalized multi-walled carbon nanotubes

In order to improve the conductivity of Sb: SnO2 (ATO) films, very thin multi-walled carbon nanotubes (MWNNTs) functionalized with -NH2 and -COOH groups have been investigated. The new nanocomposites were prepared by the addition of such MWNTs pre-dispersed in a cationic surfactant (Hexadecyltrimethyl ammonium chloride) in the ATO sol at concentrations of 0.05 and 0.1 wt%. Coatings of pure ATO and nanocomposites were prepared by spin coating on borofloat glass substrates. Experiments showed that all coatings containing nanotubes present resistivities of the order of 10(-1) to 10(-2) Omega cm while pure ATO films prepared under the same conditions show resistivities which are about 16 times higher. Optical transmission in the visible range of all systems studied was about 90%. The results indicate the suitability of MWNTs as additives for enhancing electrical properties of transparent conductive coatings. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim