Dichloro‐Functionalized Urea Additive for Crystal Regulation in Stable Perovskite Photovoltaics

ABSTRACT Developing passivators that deliver multi‐mechanistic synergistic effects constitutes a highly efficacious strategy for crystallization regulation, while simultaneously serving as a critical approach to bolster the long‐term operational stability of perovskite solar cells. In this work, a series of amine‐derived functional additives was rationally engineered and systematically evaluated via molecular design strategy to precisely regulate both the substitution pattern and the chlorine atoms count. Notably, the dichloro‐substituted derivative 1‐(3,4‐dichlorophenyl)‐3‐(pyridin‐4‐yl)urea (DCLPU) demonstrates exceptional coordination passivation capability, an effect predominantly ascribed to the significantly enhanced electronegativity of its carbonyl group. This modification markedly reduces the perovskite crystallization rate and directs the preferential orientation of the perovskite (100) crystal facet. Furthermore, DCLPU suppresses non‑radiative recombination losses and weakens electron‑phonon coupling via energy level modulation. Consequently, the inverted device incorporating DCLPU attained a champion power conversion efficiency (PCE) of 27.32% (certified: 26.91%), alongside a corresponding module efficiency of 22.50%. These devices further exhibited outstanding thermal stability, ultraviolet resistance, and sustained operational durability. This work delineates a robust and practicable paradigm for advancing high‐efficiency, stable perovskite photovoltaic technologies.