Effects of Ti 3 C 2 Tx MXene Addition to a Co Complex/Ionic Liquid-Based Electrolyte on the Photovoltaic Performance of Solar Cells.

Redox mediators comprising I - , Co 3+ , and Ti 3 C 2 Tx MXene were applied to dye-sensitized solar cells (DSCs). In the as-prepared DSCs (I-DSCs), wherein hole conduction occurred via the redox reaction of I - /I 3 - ions, the power conversion efficiency (PCE) was not altered by the addition of Ti 3 C 2 Tx MXene. The I-DSCs were exposed to light to produce Co 2+ /Co 3+ -based cells (Co-DSCs), wherein the holes were transferred via the redox reaction of Co 2+ /Co 3+ ions. A PCE of 9.01% was achieved in a Co-DSC with Ti 3 C 2 Tx MXene (Ti 3 C 2 Tx-Co-DSC), which indicated an improvement from the PCE of a bare Co-DSC without Ti 3 C 2 Tx MXene (7.27%). It was also found that the presence of Ti 3 C 2 Tx MXene in the redox mediator increased the hole collection, dye regeneration, and electron injection efficiencies of the Ti 3 C 2 Tx-Co-DSC, leading to an improvement in both the short-circuit current and the PCE when compared with those of the bare Co-DSC without MXene.