Ultraviolet-Curable Gel Electrolytes Enabling Efficient Dye-Sensitized Solar Cells with Low-Temperature Fabricated Photoanodes

Electrolyte leakage is a critical challenge in dye-sensitized solar cells (DSSCs), leading to poor long-term stability. Gel electrolytes (GEs) have been widely explored as an effective solution to this issue. Conventionally, GEs are prepared by incorporating polymers into liquid electrolytes; however, polymer-based GEs are unsuitable for DSSCs with low-temperature-fabricated photoanodes due to the weak mechanical stability of the mesoporous layer. Herein, ultraviolet (UV)-curable silicone monomers and UV-curable hydrophilic monomers are incorporated into a liquid electrolyte to form a GE precursor. The precursor exhibits excellent fluidity, enabling effective infiltration into the mesoporous layer, and subsequently forms a stable gel upon UV exposure. Silicone incorporation enhances ion conductivity and ion diffusivity while reducing dielectric energy loss. With the incorporation of ZnO nanoparticles, the DSSC employing GE with a 10 wt % silicone content achieves a power conversion efficiency of 5.82%, significantly improved from 4.17% and approaching that of a liquid electrolyte-based device (6.53%). This performance surpasses previously reported values for low-temperature-fabricated DSSCs employing GEs. The enhanced performance is attributed to the improvement of ion transport. However, excessive silicone incorporation adversely reduces ionic conductivity and ion diffusivity, highlighting the importance of optimized silicone content.