Evaluation of electrical conduction in iodine-doped polypyrrole

Electrical conductivity of polypyrrole has been measured after doping with different iodine concentrations. A thermally activated electrical conductivity was found which was pseudoohmic and increased with doping level. The results can also be fitted by log σ versusT ^−1/2 and log σ versusT ^−1/4 dependences, instead of the Arrhenius log σ versusT ⁻¹ dependence. From these results it was concluded that within the experimental scatter no significant distinction can be made between these different temperature dependence laws. Hence these data can only enable one to speculate about the true underlying transport model, rather than to draw decisive conclusions. Electrical conductivity results predicting the role of iodine dopant concentration on the conduction process of semiconducting polypyrrole are discussed.