Influence of Electrode Rotation on the Growth and Impedance of a Low Band Gap Conducting Polymer

Rotation of the electrode during the electrochemical polymerization of Δ4,4‘-di-cyclopenta[2,1-b;3‘,4‘-b‘]-dithiophene results in enhanced rates of film growth on the electrode and changes in morphology from dominantly fibrilar to globular structures. The impedance of the resulting films shows their ionic conductivities to be higher than their electronic conductivities. Rotating the electrode during growth enhances electronic conductivities by as much as 2 orders of magnitude, and this is attributed to the dominance of growth of the polymer on the electrode surface (grafting) over the precipitation of material from the diffusion layer.