Redox Switching in Conjugated Polymer Thin Films

Redox Switching in Conjugated Polymer Thin Films 

In this section we examine the mechanism of potential induced redox switching in electronically conducting polymer Aims. The term redox switching refers to the transition from an electronically insulating to an 

FIGURE 1.26. (a) Schematic representation of the oxidized site distribution in an electronically conducting polymer film according to the Aoki phase propagation model, (b) Conductive front propagation modeled as a random distribution of oxidized chains with each chain starting from a random location on the support electrode surface, (c) An assembly of conductive one-dimensional pillar fibrils of various lengths. 

FIGURE 1.27. Schematic representation of conductive cylinders. Shaded regions are conductive unshaded regions are insulating. Both intramolecular and intermolecular interfaces are illustrated. 

Let a and b denote concentrations of reduced and oxidized species present in the film and at any time t the total site concentration Cx = a + b, whereas at time t = 0, b = 0 and Cx - a. Now charge transfer across the conducting/nonconducting boimdary is given by the Butler-Volmer expression 

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