Removable Additive Assists Blade-Coated Large-Area Organic Solar Cell Modules Fabricated with Non-Halogenated Solvents Achieving Efficiency Over 16%

The critical step in commercializing organic solar cells (OSCs) involves achieving high-performance modules through environmentally friendly solvents. The incorporation of solid additives, recognized as an effective method for modulating the morphology of active layers through layer-by-layer (LBL) deposition, plays a significant role. Here, a novel volatile solid additive is introduced individually into the non-halogenated solution of donor PM6 as a morphology-modulating agent. The additive induces conformational and crystalline orientation change of PM6, resulting in enhanced and balanced charge transport in the active layer. With a focus on exciton dynamics, the optimized active layer inhibits the formation of low-energy triplet states. It facilitates strong reverse hole transfer processes, leading to more efficient exciton dissociation. The final small-area LBL blade-coated OSCs fabricated under ambient conditions achieve a power conversion efficiency (PCE) of 18.42%. Furthermore, a large-area module with an area of 28.82 cm2 is manufactured, achieving a PCE of 16.04% with a high geometric fill factor of 93.8%. This highlights the effective modulation of the active layer through the use of solid additives and provides a successful strategy for fabricating high-performance OSC modules with non-halogenated solvents. The PM6: BTP-eC9-based large-area (28.82 cm2) modules yield an impressive power conversion efficiency of 16.04% with a small cell-to-module loss. The result suggests the effectiveness of the volatile solid additive methyl nicotinate in regulating the active layer morphology and paves a new path for the fabrication of highly efficient and scalable large-area organic solar cell modules with non-halogenated solvent. image