Improved preparation of polybenzo[c]thiophene-modified electrodes employing p-toluenesulfonate as dopant anion

Use of tetraethylammonium p-toluenesulfonate (TEATos) as electrolyte for electrodeposition of polybenzo[c]thiophene from CH3CN solution gives compact, smooth films on indium-doped tin oxide electrodes. These grow at lower overpotentials, and with fewer problems of film inhomogeneity, than films grown using tetrafluoroborate electrolytes. Films up to 10 μm thick have been deposited with TEATos, but film growth is self-limiting with tetraethylammonium tetrafluoroborate (TEAT). TEATos-grown films have a different morphology, but can still be reversibly p-doped in the same way as TEAT-grown films. n-Doping, however, is not electrochemically improved by using TEATos as growth electrolyte.