High‐Voltage Quasi‐Solid‐State Dye‐Sensitized Solar Cells Based on Copper Redox Shuttles

Electrolyte with copper redox shuttles has endowed dye‐sensitized solar cells (DSSCs) with a high open‐circuit voltage ( V oc ) over 1.0 V and promising efficiencies under the sun and indoor light, but further combining these copper redox shuttles with quasi‐solid‐state gel polymer electrolytes (GPEs) is still a great challenge. The crystallization of polymers inside GPEs is one of the important factors to limit the mass transport of large‐sized copper redox shuttles and dramatically reduce the efficiency of quasi‐solid‐state DSSCs. Herein, the copper‐based GPEs are fabricated via in situ UV‐induced copolymerization of acrylic monomers. This chemical cross‐linking strategy can significantly reduce the crystallinity of polymers inside the GPEs and thus improve the apparent diffusion coefficient two times compared with the generally used poly(ethylene oxide) GPEs. Finally, optimized GPEs, copolymerized by diacrylic and triacrylic monomers, successfully generate the quasi‐solid‐state DSSCs with an efficiency of 10.1% and a high V oc of 1.03 V. These photovoltaic parameters are comparable to those of DSSCs with liquid copper‐based electrolytes, demonstrating that the chemical cross‐linking is an effective strategy to fabricate high‐performance copper‐based GPEs. This strategy will facilitate the future efficiency and stability improvement of DSSCs for the commercial optoelectronic applications.