Moderating Crystallization of Wide‐Bandgap Perovskites with Dual Anchoring Passivator Enables Efficient and Stable Solar Cells and Modules

Wide‐bandgap (WBG) perovskite solar cells are essential for advancing tandem and indoor devices. However, Br‐rich WBG devices still suffer from poor morphology, significant open‐circuit voltage ( V OC ) loss, and instability due to their rapid crystallization and defect‐rich nature to date. Herein, an amino acid derivative additive, N ‐(Chloroacetyl)glycine ethyl ester (CGEE), is introduced to address the above challenges. It is found that CGEE effectively regulates the pace of perovskite crystal growth through dual interactions with PbI 2 and FAI. Furthermore, the carbonyl group of CGEE passivates perovskite defects, therefore suppressing nonradiative recombination and enhancing stability of the devices. By leveraging the multifunctional properties of CGEE, it can retard crystallization process, mitigate film stress, improve interfacial energetic alignment, and passivate lattice defects. With these merits, small‐area inverted devices achieved a champion efficiency of 22.23% (compared to 20.68% in control device) and an exceptional fill factor of 85.59%, with negligible efficiency decay over 1000 h observation period. Additionally, a 5 × 5 cm mini‐module with an effective area of 12.8 cm 2 is fabricated, exhibiting good uniformity and achieving a champion efficiency of 16.4%. These findings provide new insights for preparing efficient and stable WBG perovskite devices for future tandem and indoor applications.