Geometry-dependent monolayers for efficient inverted perovskite solar cells

Record efficiencies in inverted perovskite solar cells (PSCs) are increasingly depend on precise energetic and electronic matching of self-assembled monolayers (SAMs) at buried interfaces(1-6). Yet most SAM designs address only one dimension of interfacial control, emphasizing either defect passivation at the perovskite contact or work-function alignment at the electrode (7-10). Moreover, hopping-mediated charge transport across the functional monolayer is often overlooked (11-13). Here we establish a geometry-dependent three-layer molecular-contact framework by integrating a multiple-site fixation strategy with fusion-topology reconfiguration of a benzothienocarbazole scaffold, enabling bidirectional anchoring and geometry-tailored frontier-orbital coupling across both interfaces. The resulting interfacial synergy suppresses defect formation, facilitates charge extraction, and therefore delivers a record high power conversion efficiency (PCE) of 28.11% (27.78% certified) in inverted PSCs, while retaining over 95% of the initial efficiency after 1,500 hours aging according to ISOS-L-2 protocol. This work defines a transport-aware, dual-interface-anchored SAM design model that enables the synergistic optimization of interfacial energetics, defect passivation and charge-transfer kinetics within a unified molecular framework.