Synergistic Spatial Charge Distribution Enhancing Electron Affinity to Afford High‐Efficiency Perovskite Solar Cells

ABSTRACT Additive engineering emerges as an effective approach to achieve high‐performance perovskite solar cells (PSCs), playing a crucial role in suppressing intrinsic perovskite defects and regulating grain growth. In this work, we report a versatile additive engineering strategy for multi‐site perovskite passivation using 1,3‐bis[4‐(trifluoromethoxy)phenyl]urea (BFPU) or 1,3‐bis(4‐cyanophenyl)urea (BCPU). The as‐designed two additives feature amino and carbonyl groups positioned between two benzene rings to interact with uncoordinated ion vacancies and halides in perovskite, passivating the defect sites and optimizing crystallization. Moreover, trifluoromethyl ends of BFPU coordinate with perovskite organic cations while strong electron‐withdrawing cyano ends of BCPU bond strongly with Pb 2+ ions, enhancing perovskite phase stability. The multi‐site coordination of BFPU/BCPU endows the perovskite with improved charge transport, suppressed non‐radiative recombination, large‐grain low‐defect films, and thus enhanced PSCs stability. The additive‐engineered PSCs of BFPU/BCPU achieved the highest power conversion efficiency (PCE) of 25.32% and 25.68% over 0.09 cm 2 device area, respectively. Impressively, the additive engineering of BFPU/BCPU enables champion PCEs of 23.28% and 23.43% for single‐junction wide bandgap (1.68 eV) PSCs, along with excellent operational stability. Such synergistic multi‐site coordination design demonstrates a universal additive strategy for different bandgaps perovskites, opening a promising avenue for fabricating high‐efficiency stable PSCs.