Connectivity of conducting crystalline networks in reticulate doped polymers

Abstract

Measurements of temperature dependences of conductivity for morphologically different samples of reticulate doped polymers containing dentrite-like microcrystals of a conducting charge-transfer (CT) complex demonstrate that there is no difference in the mechanism of charge carrier transport along dendrite branches, perpendicular to them or across interdendrite boundaries. Comparison of the conductivity behaviour, as measured along polymer films and perpendicular to the surfaces ('sandwich' samples), suggest that the same mechanism of conductivity operates in both directions. It is also demonstrated that lowering of the CT complex content, even to 0.003 vol. fraction, leads to some decrease of the conductivity but does not change its temperature dependence. The results demonstrate the high connectivity of the crystalline CT complex network and support the hypothesis that continuity of this network is due to submicroscopic dendritic structures scaling from microns, probably down to tens of angstroms.