Improvement of Carbon-Based Counter Electrode for Dye-Sensitized Solar Cells

A ClO4−-doped poly(3,4-ethylenedioxythiophene) (PEDOT)-supported carbon particle (PEDOT–ClO4−/C) composite film electrode was prepared by electrophoretic deposition on transparent conductive oxide glass to improve the performance of carbon-based counter electrodes for dye-sensitized solar cells (DSSC). Evaluation of the electrochemical impedance demonstrated that the PEDOT–ClO4−/C composite film electrode had a lower iodide electrolyte/electrode interfacial resistance than that of a simple carbon particle film electrode. As a result, a DSSC with a PEDOT–ClO4−/C composite film counter electrode had a significantly improved fill factor and photovoltaic conversion efficiency, compared to a cell based on a simple carbon particle film electrode. Furthermore, the photovoltaic conversion efficiency of a DSSC with a PEDOT–ClO4−/C composite film electrode demonstrated approximately 85% of the conversion efficiency of a DSSC with a platinum-sputtered glass counter electrode.