Precisely‐Controlled Co‐Self‐Assembled Monolayer for Improved Performance of Blade‐Coated Perovskite Solar Cells

Abstract Self‐assembled monolayers (SAMs) have achieved remarkable success in the realm of inverted perovskite solar cells (PSCs). The integration of two distinct SAMs, referred to as co‐SAM, significantly broadens the diversity within the SAM family and propels the enhancement of PSC performance. In this study, a co‐SAM consisting of [4‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)butyl] phosphonic acid (MeO‐4PACz) and [2‐(3,6‐dimethyl‐9H‐carbazol‐9‐yl) ethyl] phosphonic acid (Me‐2PACz) is sequentially deposited to achieve a precisely controlled nanostructure. It is unveiled that the initial deposition step governs the surface wettability, whereas the subsequent step dictates the energy level alignment. Leveraging this meticulously regulated co‐SAM, the blade‐coated PSC attains an impressive efficiency of 25.01%, retains 95.4% of its efficiency after 2500 h under illumination, and maintains 86.7% of its efficiency after ≈2000 h at 85 °C. This research delineates a novel pathway to facilitate the large‐scale manufacturing of PSCs.