Highly efficient and stable quasi-solid-state dye-sensitized solar cells with PEO/PMMA/single‑layered graphene oxide composite electrolytes

High-performance gel polymer electrolytes based on polyethylene oxide/polymethyl methacrylate (PEO/PMMA) incorporating different weight percentage of single-layered graphene oxide (GO) nanosheets were prepared by a solution method for dye-sensitized solar cell applications. The measured ionic conductivity and thermal properties of electrolytes exhibited that these characteristics can be increased with the introduction of graphene oxide into PEO/PMMA based gel electrolyte. The results revealed that the highest ionic conductivity of gel polymer electrolyte was 14.5 mS·cm −1 at 1 wt% of graphene oxide nanosheets. Solar cell composed of optimized polymer gel electrolyte (PEO/PMMA/GO-1) revealed a 6.98% photon conversion efficiency, which was more than neat PEO/PMMA gel electrolyte (4.92%). This finding can be related to the higher ionic conductivity of the composite electrolytes as a result of the addition of graphene oxide nanosheets. Electrochemical impedance analysis showed that charge recombination resistance of gel electrolyte can be increased in the presence of graphene nanosheets. The long-term stability study showed that after 600h of testing, the optimized solar cell (PMMA/PEO/GO-1) had very significant durability as compared to the cell fabricated with liquid electrolyte.