Compatibilizer-Mediated Aggregation Suppression Enables High-Performance Organic Photovoltaic Modules Processed From Green Solvents.

Prolonged film formation from green solvents often induces excessive aggregation. This remains a critical challenge for the scalable fabrication of high-performance organic photovoltaic (OPV) modules. Herein, we show that a rationally designed giant molecule, D-IO, can serve as an effective third component to suppress aggregation. Employing PM6:BTP-eC9 as a representative host blend, D-IO effectively modulates donor-acceptor interactions by enhancing their compatibility, thereby promoting cooperative assembly and inhibiting the uncontrolled growth of large aggregates during film formation. This yields a well-defined fibrillar network morphology while preserving desired molecular packing and charge transport pathways. Consequently, small-area devices processed with the green solvent o-xylene achieve a champion power conversion efficiency (PCE) of 19.71%. More importantly, this strategy is readily applicable to large-area fabrication. Blade-coated modules with active areas of 9.97 and 26.6 cm2 achieved PCEs of 17.26% and 15.49%, respectively. This work provides an effective morphological regulator for high-performance OPV modules processed from green solvents.