Highly transparent dye-sensitized solar cells with UV-absorbing fluorene dyes and tetramethylthiourea electrolytes

This study demonstrates the development of highly transparent dye-sensitized solar cells (DSSCs) through the strategic combination of UV-absorbing, metal-free dyes and a novel non-iodine-based electrolyte system. We systematically investigated four UV-absorbing dyes - FCA, FQA, FPCN, and FFCN - with the FPCN emerging as the optimal candidate, demonstrating superior visible light transmittance while maintaining effective power conversion efficiency (PCE). When coupled with a tetramethylthiourea/tetramethyl formamidinium disulfide (TMTU/TMFDS²⁺) electrolyte system, the FPCN-sensitized solar cells achieved remarkable visible light transmittance (VLT) exceeding 68% alongside a PCE of 1.58%, surpassing the performance metrics of conventional [Formula: see text] systems. The implementation of the non-iodine electrolyte significantly enhanced the optical properties, as quantified by improved chromaticity coordinates and color rendering index (CRI) values, establishing these cells as viable candidates for transparent solar panel applications. Our findings demonstrate that the synergistic combination of UV-absorbing dyes and non-iodine electrolytes enables the development of highly transparent, aesthetically appealing DSSCs.