Electrocatalytic SiC Nanoparticles/PEDOT: PSS Composite Thin Films as the Counter Electrodes of Dye-Sensitized Solar Cells

A composite film consisting of silicon carbide nanoparticles and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (SiC-NPs/PEDOT:PSS) is deposited on a fluorine-doped tin oxide substrate and used as the counter electrode (CE) material for a dye-sensitized solar cell (DSSC). The content of SiC is optimized to be 5wt% with respect to PEDOT:PSS to obtain the best power conversion efficiency (η) of 7.25% for the pertinent DSSC. The η of the best DSSC (7.25%) is found to be slightly lower than that of the cell with a sputtered-Pt CE (η=7.98%). The films are characterized by using field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. Electrocatalytic parameters of the CEs are obtained by using cyclic voltammetry, rotating disk electrode, and Tafel polarization curves. Electrochemical impedance spectroscopy and incident photon-to-current conversion efficiency curves are used to substantiate the photovoltaic parameter.