Perovskite Solar Cells Based on Regulated Crystallization of Multifunctional Pyridine Molecules

The crystallization of perovskite films is highly sensitive to environmental conditions and fabrication processes, often leading to defect formation. Precise control over the ordered crystallization of perovskites is crucial for achieving high-performance perovskite solar cells. In this work, we propose a doping strategy using 6-chloropyridine-3-sulfonamide (6-CPS) to modulate perovskite crystallization. The multifunctional 6-CPS molecule, including the sulfonamide group (-SO₂NH₂), pyridine ring (C₅H₅N), and chlorine atom (Cl), enables strong multisite coordination with perovskite components. These unique interactions effectively regulate the perovskite crystallization process, yielding high-quality perovskite films with optimized morphology and reduced defect density. Furthermore, 6-CPS modification improves energy level alignment and enhances the optoelectronic performance of the devices. As a result, the optimized 6-CPS-modified devices achieved a champion power conversion efficiency (PCE) of 24.56%. Notably, the 6-CPS-treated devices exhibit significantly improved stability, retaining 85.44% of their initial PCE after 720 h of accelerated aging under 65 ± 5% relative humidity.