Preparation and Performance of Polyaniline/Graphite Composite Counter Electrodes for Dye-sensitized Solar Cells

The aim of this study is to balance the conductive properties with catalytic activity of the counter electrodes effectively and to resolve the complexity of production process. Using a kind of network conductive polyaniline as the catalyst and graphite filler as the conductive material, by means of screen printing the mixture of the two components on the FTO surface the polyaniline/graphite composite counter electrodes were fabricated successfully. The structure and catalytic and conductive characteristics of the electrodes were investigated with the scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). According to the SEM results, the network structure of conducting polyaniline still exists in the composite. The addition of graphite fills the space of the polyaniline matrix effectively. Based on the same original catalytic activity,the electrical conductivity of the counter electrode has been enhanced. With the aid of CV and EIS, the catalytic and conductive characteristics of the composite counter electrode were speculated. Tests on the photoelectric performance of the DSSCs with the composite counter electrodes show that when the graphite mass fraction reaches 10%, the dye-sensitized solar cell (DSSC) based on the polyaniline/graphite composite counter electrode may have the photoelectric conversion efficiency of 8. 5%. It is 123% of the efficiency with traditional Pt electrode under the same conditions.