Tailoring Dual‐Site Defect Passivation Molecules to Minimize Buried Interface Energy Loss for Highly Efficient and Stable Perovskite Solar Cells

Abstract The modification of interfaces in perovskite solar cells (PSCs) to achieve mitigation of carrier transport barriers and suppression of non‐radiative recombination is essential for enhancing PSC efficiency and stability. In this study, two small dipole‐functionalized molecules, 1,4‐di(thiophen‐2‐yl)benzene and 1,4‐di(thiazol‐2‐yl)benzene, were synthesized and effectively anchored onto perovskite surfaces via Lewis acid‐base interactions to improve the quality of perovskite grain boundaries and reduce non‐radiative recombination. The dual‐passivation‐site dipole‐functionalized molecules strategically modulate the interfaces, establishing a gradient energy level alignment, that facilitates carrier extraction and transport. As a result, the optimal n‐i‐p PSC achieved a champion power conversion efficiency (PCE) of 25.85% alongside enhanced operational stability under simulated 1‐sun illumination over 1200 h. A large‐area device with an area of 1 cm 2 also exhibited a PCE of 24.79%. Our study provides fundamental insights into the role of dipole molecules in defect passivation for further development of interfacial engineering strategies for high‐performance perovskite optoelectronic devices.