New Inorganic-Organic Hybrid Gels Based on SnI2 + I2 for High-Performance Quasi Solid-State Dye-Sensitized Solar Cells

This work introduces new inorganic-organic hybrid gel electrolytes for quasi-solid dye-sensitized solar cells (qss-DSSC). Parent gel ( G2 ) contains components of SnI 2 , I 2 , 4-tert-butylpyridine (TBP) and ethylene glycol monomethyl ether (EGME), forms a gel after being sealed in air for about 2 weeks. TBP, EGME and Sn 4+ were proved essential for crystalline gel. Based on G2 , by selectively adding iodide salts, modified gels were obtained, namely G2-DMII , G2-LiI , G2-CsI , G2-CsI-LiI and G2-CsI-DMII , respectively. They were systematically characterized by XRD, SEM, FT-IR, TGA, UV-Vis, CV, EIS and LSV. Compared to G2 , the modified gels show coarser structure with obvious grain boundaries and more surface cavities, and the electrical properties were significantly improved. Among them, G2-CsI-DMII is the most uniform and densest, exhibiting the highest ionic conductivity of 7.22 × 10 −4 S cm −1 and the I 3 − diffusion coefficient of 8.52 × 10 −6 cm 2 s −1 . When integrated into N719-dye based qss-DSSCs, higher PCE of 10.68% under one-sun was achieved. Under indoor light of 10000 lux, the PCE soared to 31.96%, demonstrating the prepared gel electrolyte is efficient and has good adaptability in qss-DSSC applications across diverse lighting conditions. This study offers innovative ideas for designing new gel electrolyte in high-performance solar energy conversion applications.