Unleashing the potential of Cu1+/2+ blended quasi-solid-state electrolytes for long-term stability of dye-sensitized solar cells

The pursuit of long-term stability in dye-sensitized solar cells (DSSCs) is crucial for their commercialization. One of the main challenges in achieving long-term stability is the electrolyte. However, concerns about efficiency and long-term stability have hindered the transition of DSSCs from the laboratory to industry and outdoor applications. A recent innovation in this field involves the use of blend combinations of copper redox mediators with nanoparticles in a polymer electrolyte medium, which offers significant advantages. Herein, we introduce a new metallic oxide nano-structure to enhance conductivity and reduce resistivity in a quasi-solid-state electrolyte (QSSE) medium. A comparative study was conducted between synthesised nanoparticles with a copper redox couple ([Cu(ptpbi)2]1+/2+) and an organic additive (MPP) in blend bio-polymer electrolytes. The inclusion of nanoparticles had a positive impact on the light-to-electricity conversion efficiency, which reached 6.19 %, higher than that of the device without nanoparticles. The addition of nanoparticles to the QSSE strongly altered the energy level alignments, reduced recombination at the electrode-redox electrolyte interfaces, and increased the dark exchange current density. The electrical surface-state modifications induced by the diffusion of Cu1+ metal ions in the electrolyte played a significant role in controlling aggregation and charge transfer kinetics.