Effects of Ti₃C₂Tx MXene Addition to a Co Complex/Ionic Liquid-Based Electrolyte on the Photovoltaic Performance of...

Redox mediators comprising I^-, Co³⁺, and Ti₃C₂Tx 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^-/I₃^- ions, the power conversion efficiency (PCE) was not altered by the addition of Ti₃C₂Tx MXene. The I-DSCs were exposed to light to produce Co²⁺/Co³⁺-based cells (Co-DSCs), wherein the holes were transferred via the redox reaction of Co²⁺/Co³⁺ ions. A PCE of 9.01% was achieved in a Co-DSC with Ti₃C₂Tx MXene (Ti₃C₂Tx-Co-DSC), which indicated an improvement from the PCE of a bare Co-DSC without Ti₃C₂Tx MXene (7.27%). It was also found that the presence of Ti₃C₂Tx MXene in the redox mediator increased the hole collection, dye regeneration, and electron injection efficiencies of the Ti₃C₂Tx-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.