Vacuum-induced interfacial compaction for scalable fabrication of high-performance organic solar cells

Organic solar cells hold great promise for next-generation photovoltaics, yet their practical deployment is impeded by intrinsic morphological and interfacial limitations that compromise device performance and stability. Herein, we introduce a vacuum-induced interfacial compaction strategy that forms smooth, compact, and strongly adhered multilayer films without conventional thermal or solvent annealing, by promoting dense stacking, suppressing interfacial voids, and improving overall interfacial integrity. Consequently, corresponding devices achieve power conversion efficiencies of 20.51% for rigid and 19.13% for flexible devices, together with a high yield. Notably, device with an active area of 1.0 cm2 and a module with an area of 15.7 cm2 fabricated with this strategy deliver efficiencies of 19.04% and 17.48%, respectively. Upon further scaling the module area to 67.2 cm2, a high efficiency of 15.37% is still attained. These results establish the vacuum-induced interfacial compaction strategy as a feasible route toward durable, high-performance organic solar cells. Organic solar cells face morphological and interfacial limits that reduce efficiency and stability. The authors present a vacuum-induced compaction method that builds dense, smooth interfaces, delivering large area-scalable high-performance devices.