Unlocking 27.3% perovskite photovoltaics by interface-locked dual-molecule contact

Inverted perovskite solar cells (PSCs) remain constrained by nickel ion (Ni 3+ )–triggered interfacial redox chemistry and buried-interface defect landscapes that drive nonradiative loss and undermine operational stability. We report an interface-locked dual-molecule contact by coassembling [4-(3,6-dimethyl-9 H -carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) with 9 H -carbazol-2-yl trifluoromethanesulfonate (CzOTf), in which π-π–stabilized cofacial packing rigidifies molecular orientation and strengthens interfacial electronic coupling for efficient hole extraction, whereas the sulfonate terminus offers broader lead (Pb)–related defect coordination and relieves interfacial tensile stress, collectively promoting higher-quality crystallization and a chemically stabilized buried interface. Enabled by this synergistic regulation, vacuum-flash-evaporated 1.53–electron volt PSCs deliver certified efficiencies up to 27.31%. The strategy also translates to perovskite/HJT-Si (silicon heterojunction) tandems with an efficiency of 32.84%. Furthermore, the corresponding 766–square centimeter large-area module achieved a power conversion efficiency of 21.54%. The CzOTf-modulated PSCs retain 92% of their initial efficiency after 2000 hours of continuous light soaking (ISOS-L-1). The CzOTf-modulated large-area module operated stably outdoors for 35 days without degradation.