Affordable excellence: unveiling the potential of graphitic carbon-based counter electrodes for high-performance dye-sensitized solar cells

Dye-Sensitized Solar Cells (DSSCs) have emerged as a promising alternative energy technology due to their minimal material requirements and straightforward production process, enabling efficient performance even under low-light conditions. Traditionally, high-performance DSSCs utilize platinum as the counter electrode. However, the high cost of platinum necessitates the development of more affordable counter electrodes that can match or surpass platinum-based counter electrodes (CEs) in conversion efficiency. This study investigates the synthesis and application of various cost-effective counter electrodes, including candle flame carbon soot, pencil lead graphite, and CS-coated PLG, in highefficiency DSSCs. For comparison, a platinum-based counter electrode is used as a benchmark. The working electrode comprises TiO2 on Fluorine-Doped Tin Oxide substrates. The DSSCs fabricated with counter electrodes such as PLG, CS, and CS-coated PLG exhibit efficiencies of approximately 6.2%, 3.5%, and 8.5%, respectively, compared to 10.8% for the Pt-based counter electrode. Reduced series resistance contributes to an improved Fill Factor and increased conversion efficiency. Furthermore, impedance spectroscopy reveals higher capacitance at the CE/electrolyte interface, enhancing charge collection efficiency and electron lifetime. Thus, the potential for significant improvement in conversion efficiency makes low-cost PLG and carbon-based electrodes a highly attractive alternative to Pt-based electrodes.