Sustainable\nMolecular Passivation via Heat-Induced\nDisaggregation and Redox Reactions for Inverted Perovskite Solar Cells

Molecular materials with high structure-design freedom\nare used\nas new interface passivators to reduce nonradiative recombination\nin inverted perovskite solar cells (PSCs). However, most molecular\nmodifiers are unable to achieve a long-term passivation effect due\nto self-aggregation. Here, the molecular modifier 1-methyl-2-thiomethyl-1<i>H</i>-imidazole-5-carboxylate (SMC) with ester and thiol groups\nis carefully developed. The ester groups weaken self-aggregation triggered\nby intermolecular hydrogen bonds, making such aggregations easier\nto disassemble during heating to form a net-like insulating layer\nwith random openings, which dramatically increase charge transport.\nMore importantly, the electron transfer between thiol and disulfide\ncan accelerate the elimination of Pb<sub>0</sub> and I<sub>2</sub> by redox reactions to prevent phase separation. Ultimately, the\noptimized inverted PSCs with bandgaps of 1.68 and 1.55 eV showed surprising\nfill factors of 84.83% and 86.18%, resulting in champion efficiencies\nof 23.45% (certified 22.98%, which is the highest to date for wide-bandgap)\nand 25.71% (certified 25.28%), respectively. Remarkably, both unencapsulated\ndevices maintained over 94% of their initial efficiency under maximum\npower point tracking for 600 h (50 °C) and 1000 h (65 °C),\nrespectively, confirming impressive long-term operational stability.