Aromatic Interaction Tailored Interfacial Chemical Reactivity of the Perovskite/Self‐Assembled Monolayers for Efficient and Stable Perovskite Solar Cells

ABSTRACT The perovskite/self–assembled monolayer (SAM) interface critically determines the efficiency and stability of perovskite solar cells (PSCs). However, uncontrolled interfacial chemical reactivity at this interface not only influences charge transport properties and interfacial stability, but also governs the nucleation and crystallization of the overlying perovskite film. Here, we analyze thermodynamic instability and degradation mechanisms of the conventional NiO x ‐SAM/perovskite interface, and introduce bisphosphonate molecules with distinct conjugation interactions into NiO x to tailor the interfacial chemical reactivity. Among our bisphosphonate molecules, zoledronic acid with an imidazole ring reduces interfacial chemical reactivity and forms a robust interface that directs perovskite crystallization toward slower, defect‐healed, and highly ordered growth, due to the highest degree of conjugation. The corresponding inverted perovskite solar cells achieve remarkable power conversion efficiencies of 26.67% (active area, 0.075 cm 2 ), 21.68% (active area, 10.04 cm 2 ), and 21.06% (active area, 650 cm 2 ), respectively, underscoring the universality of this strategy for commercial‐scale manufacturing. The devices also exhibit remarkable durability, retaining >97% of their initial efficiency after 3000 h of ISOS‐D‐1 storage (extrapolated T 90 > 14,000 h) and >93% after 900 h under ISOS‐L‐1 maximum‐power‐point tracking, showcasing their exceptionally high stability compared to previously reported PSCs.