Homogeneously Contacted Co‐Self‐Assembled Monolayer Enables over 26% Inverted Perovskite Solar Cells

ABSTRACT Carbazole‐based self‐assembled monolayers (SAMs), widely utilized as a hole‐contacting layer in inverted perovskite solar cells (PSCs), exhibit micelle formation in solution that diminishes interfacial uniformity. Herein, a series of fluorinated conjugated SAMs (DCA‐0F, DCA‐1F, and DCA‐2F) is designed and successfully synthesized to develop a co‐SAMs for high‐performing inverted PSCs. In general, these dimethylacridine‐based SAMs exhibit a unique molecular structure with sufficient steric hindrance to suppress self‐aggregation at the solution state. Besides, fluorine atoms can stabilize the FA cations via hydrogen bonding that provides more anchoring sites at the buried interface, which is beneficial for facilitating carrier extraction and transport and suppressing interfacial losses. Consequently, inverted PSCs fabricated with the DCA‐0F, DCA‐1F, and DCA‐2F co‐SAMs achieved champion power conversion efficiencies of 25.21%, 26.11%, and 25.05%, respectively. Furthermore, these devices exhibited exceptional operational stability, retaining approximately 90% of their initial efficiency following 1000 h of continuous operation at the maximum power point under 1‐sun illumination. This work establishes a viable pathway for designing well‐dispersed and highly effective SAMs that effectively overcome key interfacial challenges in inverted PSCs.