Is granularity the determining feature for electron transport in conducting polymers ?

From several studies of transport properties of conducting polymers (CP) as a function of a parameter related to their structure or microstructure we show that in strongly disordered CP, electron transport is dominated by hopping between conducting grains separated by insulating barriers. In CSA-protonated polyaniline, a weakly disordered CP which exhibits a metallic-like behaviour, several results indicate that heterogeneities play a major role in the transport process. Thus, we conclude that heterogeneous disorder appears as a key parameter which controls the conductivity of a large majority of CP.