Nature of Conduction and Relation with CP Morphology

Conduction in CPs, as opposed to that in conventional inorganic semiconductors such as doped GaAs or Si for instance, is often said to be a redox conduction rather than an electronic conduction or conventional Ohmic conduction , because it is ascribed predominantly to charge carriers, such as bipolarons, rather than to electrons. 

This is substantially but not entirely correct for several reasons. Firstly, these bipolarons and other charge carriers are not truly mobile, coasting along from one end of an infinite polymer chain to another, as in the idealized 1-d conduction model. Rather, they are localized or confined by features such as defects or discontinuities in the extended conjugation (for example an sp defect in the idealized sp extended conjugation of P(Ac) or a cross link or ortho branch in the idealized head-to-tail chain of P(ANi)), and by attraction to dopant counterions which pin them down. 

6-1 Schematic of relation of CP morphology to conduction here showing intra/inter-chain and intra/inter-fiber relations. After Reference [165], reproduced with permission. 

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CONDUCTING POLYMERS Fundamentals and Applications 6.1.2 Nature of Conduction and Relation with CP Morphology... 

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