Graphene tailored gel electrolytes for quasi-solid-state quantum dot-sensitized solar cells

Quantum dot-sensitized solar cells (QDSCs) are promising for future renewable sources. By addressing the issues on liquid-electrolyte leakage and sluggish charge transportation, a class of graphene oxide tailored polyacrylamide (PAAm/GO) gel electrolytes are synthesized for quasi-solid-state QDSC applications. The conducting pathways with interconnected GO species can catalyze reduction reaction from Sn2− to S2− and therefore shorten charge-transfer length. Upon illumination by simulated sunlight (AM1.5, 100 mW cm−2), the optimized QDSC with PAAm/0.9% GO yields a maximized power conversion efficiency of 4.10% in comparison with 1.78% for the device free of GO. Arising from the good retention of liquid electrolyte by three-dimensional PAAM/GO framework, the final quasi-solid-state QDSCs present good long-term stability.