Graphene Quantum-Dot-Doped Polypyrrole Counter Electrode for High-Performance Dye-Sensitized Solar Cells

Herein graphene quantum dot (GQD), a graphene material with lateral dimension less than 100 nm, is explored to dope PPy on F-doped tin oxide glass as an efficient counter electrode for high-performance dye-sensitized solar cells (DSSCs). The GQDs-doped PPy film has a porous structure in comparison to the densely structured plain PPy, and displays higher catalytic current density and lower charge transfer resistance than the latter toward I-3(-)/I- redox reaction. The highest power conversion efficiency (5.27%) for DSSCs is achieved with PPy doped with 10% GQDs, which is comparable to that of Pt counter electrode-based DSSCs. This work provides an inexpensive alternative to replace platinum for DSSCs.