Novel PEDOT: PSS/graphene oxide polymer-nanocomposite counter electrodes for enhanced dye-sensitized solar cell efficiency

Dye-sensitized solar cells (DSSCs) have attracted significant attention due to their high light-to-electric energy conversion efficiency. While platinum counter electrodes boast high efficiencies, their high cost and susceptibility to corrosion have driven the search for alternative materials, including conducting polymers, carbon materials, and their nanocomposites, that have shown promising photovoltaic performance. In this study, a platinum-free DSSC utilizing a novel counter electrode comprising poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) and graphene oxide (GO) was developed. The counter electrode was prepared by drop-casting the PEDOT: PSS/GO nanocomposite onto a low-cost graphite substrate. Graphene oxide was prepared using a modified Hummer’s method and was analyzed using Raman spectroscopy and X-ray diffraction to confirm its proper formation. The morphological features, together with Raman analysis, confirmed that GO was evenly dispersed and strongly bonded with PSS chains in the nanocomposite. During DSSC assembly, a gel polymer electrolyte was inserted between the PEDOT: PSS/GO counter electrode and the five-layer TiO₂ photoanode. The best performing cell exhibited an appreciable power conversion efficiency of 2.7%, with a V_OC of 0.73 V, a J_SC of 5.21 mA cm^-2, and a fill factor of 0.71.