Inhibition of Interface Redox Reactions Through Co‐Self‐Assembled Monolayers for Efficient and Stable Inverted Perovskite Solar Cells

Abstract The NiOx/self‐assembled monolayer (SAM) hole transport bilayer has emerged as the preferred architecture for high‐performance inverted perovskite solar cells (PSCs). However, the redox reactions occurring at the NiOx/perovskite interface under photo‐thermal stress induce the degradation of perovskite, which poses severe challenges to long‐term stability. Here, tailored functionalized nicotinic acid derivatives are incorporated into commonly‐used carbazole‐based SAMs through a co‐assembled strategy. They can act as redox mediators, which not only prevent detrimental interface chemical reactions by reducing Ni ⁴⁺ , but also trigger the elimination of both Pb ⁰ and I ⁰ defects that are generated during the long‐term device operation. As a result, a power conversion efficiency of 26.03% is obtained, retaining 92.80% of the initial performance after 1,200 h of operation, following ISOS‐L‐3 protocol.