11.2% Efficiency all-polymer solar cells with high open-circuit voltage

Herein, we fabricated all-polymer solar cells (all-PSCs) based on a fluorinated wide-bandgap p-type conjugated polymer PM6 as the donor, and a narrow bandgap n-type conjugated polymer PZ1 as the acceptor. In addition to the complementary absorption and matching energy levels, the optimized blend films possess high cystallinity, predominantly face-on stacking, and a suitable phase separated morphology. With this active layer, the devices exhibited a high V _oc of 0.96 V, a superior J _sc of 17.1 mA cm ^-2 , a fine fill factor (FF) of 68.2%, and thus an excellent power conversion efficiency (PCE) of 11.2%, which is the highest value reported to date for single-junction all-PSCs. Furthermore, the devices showed good storage stability. After 80 d of storage in the N ₂ -filled glovebox, the PCE still remained over 90% of the original value. Large-area devices (1.1 cm ² ) also demonstrated an outstanding performance with a PCE of 9.2%, among the highest values for the reported large-area all-PSCs. These results indicate that the PM6:PZ1 blend is a promising candidate for scale-up production of large area high-performance all-PSCs.