Synergistic Interface Passivation and Hole Transport via Carbazole‐Based Molecules Enable Highly Efficient and Stable Perovskite Photovoltaics

ABSTRACT Carbazole‐based passivators effectively mitigate defects in perovskite films, thereby enhancing both the efficiency and operational stability of the derived devices. The defect passivation efficacy and hole extraction capability are governed by the molecular structure, encompassing the central carbazole core and the functional side chains. However, a deeper mechanistic understanding of the structure‐property relationship is essential to further optimize their passivation performance. To overcome these challenges, we introduce two distinct carbazole‐based multifunctional passivation molecules for interfacial modification. The results reveal that the carbazole passivators not only effectively suppress interfacial defects but also facilitate hole extraction owing to the intrinsic hole‐transporting properties of the carbazole moiety. Consequently, the optimized perovskite device based on N, N, N', N' ‐tetra(4‐methoxyphenyl)‐9H‐carbazole‐3,6‐diamine (4NDMCz) delivers a remarkable power conversion efficiency (PCE) of 25.56% for a small‐area device (0.09 cm 2 ) and 21.23% for a mini‐module (23.4 cm 2 ). Moreover, the devices retain over 90% of their initial efficiency after 1000 h of continuous operation under maximum power point (MPP) tracking, demonstrating excellent long‐term operational stability. This work provides valuable insights into interfacial passivation strategies for the development of efficient and stable perovskite devices.