Electrical properties of air-stable, iodine-doped carbon-nanotube-polymer composites

We report the preparation and electrical characterization of air-stable, iodine-doped single-walled carbon nanotube (SWNT)-polymer composites, which show significant enhancement in electrical conductivity by a factor of 2-5 as compared to undoped SWNT-polymer composites. The analysis of temperature dependent conductivity data reveals that the conduction of iodine-doped SWNT composites can be well described by the thermal-fluctuation-induced tunneling model. The observed substantial conductivity enhancement in iodine-doped SWNT composites can be attributed to two factors: the higher conductivity of doped SWNTs and the smaller insulating polymer barriers between adjacent conductive SWNTs. © 2007 American Institute of Physics