Highly efficient, cost-effective counter electrodes for dye-sensitized solar cells (DSSCs) augmented by highly mesoporous carbons

In dye-sensitized solar cells (DSSCs), the electrocatalyst plays a crucial role in the counter electrode as it appreciably influences the overall efficiency of DSSC. The electrocatalyst enhances the rate of the reduction reaction that converts tri-iodide into iodide ions at the counter electrode-electrolyte interface and prevents the recombination of cations in the electrolyte and the photo-generated electrons in the semiconducting material. In any catalytic process, the surface area of the electro-catalyst in the counter electrode determines the number of sites available for interactions between the reactants and the catalyst, and consequently enhances the rate of the reaction. Here, we demonstrate that electrodes based on highly mesoporous carbon (HMC) can serve as inexpensive alternatives to platinum as the electrocatalyst in DSSC. In addition, we report for the first time a systematic investigation of several materials parameters and correlate to their photovoltaic performance. In the DSSCs experiments, the HMCs display high electrocatalytic activity with power conversion (up to 8.77%) which interestingly not only outperforms other reported porous carbons but also outperforms the conventional DSSCs with Pt catalyst.