Characterization of polyaniline counter electrodes for dye-sensitized solar cells

The polyaniline counter electrodes (CEs) were electropolymerized on fluorine-doped tin oxide (FTO) glass substrates in a sulfuric acid based solution containing aniline monomers by using cyclic voltammetric synthesis. The change in thickness of polyaniline CE was controlled by means of changing the sweep-segment number. The resulting effects of sweep-segment number on the surface morphology and electrocatalytic activity of polyaniline CEs were investigated. After optimization with the sweep-segment number, the 27-sweep-segment polyaniline CE had a good electrocatalytic activity for the I−/I3− redox couple, and the DSSC assembled with such CE exhibited a good energy conversion efficiency of 5.92%, which is comparable to that of DSSC with sputtered-Pt CE.