Ti₃C₂ MXene-Reduced Graphene Oxide Composite Polymer-Based Printable Electrolyte for Quasi-Solid-State Dye-Sensitized Solar Cells

The liquid electrolyte causes the corresponding leakage and sealing problems in the construction of dye-sensitized solar cells (DSSCs). Currently, quasi-solid-state polymer-based electrolytes have been reported to effectively improve the leakage and volatilization of traditional liquid electrolytes in DSSCs. In this work, reduced graphene oxide (rGO) and the intercalation of MXene/rGO were utilized in the copolymer polyethylene oxide/poly(vinylidene fluoride-co-hexafluoropropylene) as a printable gel electrolyte for the preparation of quasi-solid-state DSSCs (QS-DSSCs). The effects of different contents of rGO and different ratios of MXene/rGO intercalation on the photoelectric performance of DSSCs were well studied. When the rGO content was 0.5 wt %, the power conversion efficiency (PCE) of DSSC was about 7.781%. Specifically, when the ratio of MXene/rGO was 2/1, the photovoltaic performance of DSSCs was greatly enhanced. The corresponding short current density (Jsc), open-circuit voltage (Voc), fill factor, and PCE were obtained to be 15.170 mA/cm2, 0.783 V, 0.695, and 8.255%, respectively. With the intercalation structure between MXene and rGO, the conductivity of electrolytes seemed to be improved through the possible shortening of transmission and diffusion distance of electrolyte ions. The printable electrolyte could achieve an energy conversion efficiency of 29.94% under 1000 lux illumination. A long-term stability (>95%) of QS-DSSCs was also achieved with the composite of MXene/rGO over 1000 h. Finally, this ready screen-printing technology with the electrolyte of the MXene/rGO composite in the copolymer would have great potential for the large-scale manufacture of flexible DSSCs in the future.