Spatially Flexible Multisite Amide Derivative Enhances the Performance of Inverted Perovskite Solar Cells and Modules

Engineering additive passivators with multiple synergistic effects has emerged as an effective strategy for regulating the growth of perovskite (PVK) grains and reducing the defect density in PVK films. In this work, a spatially flexible multisite amide derivative n‐(tert‐butyl)‐4‐ureidobenzamide (NUNB) is introduced into PVK to not only passivate defects through the interactions between its spatially flexible C═O/N─H functional groups and PVK, but also regulate the crystallization process by forming hydrogen bonds with FA + /MA + , resulting in high‐quality PVK films with larger grain sizes, less residual tensile stress and lower defect densities. Meanwhile, NUNB can effectively modulate charge transport behavior, inhibit trap‐assisted non‐radiation recombination, and enhance the stability of perovskite solar cells (PSCs). Consequently, NUNB‐treated PSC achieves an excellent power conversion efficiency (PCE) of 26.34% (certified 26.03%), along with outstanding thermal and operational stability. Furthermore, the associated rigid modules substantiate this strategy of scalable potential, achieving efficiencies of up to 21.92%.