Abstract
External single additives have played a key role in achieving high-performance organic solar cells (OSCs) by regulating the active layer morphology. Herein, we added a binary additive (naphthalene + 1-iodonaphthalene) to the PM6:L8-BO active layer. Interestingly, the binary additive simultaneously enhanced current-density (J (sc)) and fill factor (FF) to realize state-of-the art power conversion efficiency (PCE) of 18.57%, compared to a pristine device PCE (17.25%). This enhancement in performance is predominantly ascribed to (1) improved photoactive material solubility; (2) balanced mobility; and (3) optimized nanoscale morphology. In addition to the high efficiency of the binary additive-based PM6:L8-BO OSCs, these devices exhibited remarkable long-term stability, retaining up to 97% of their initial performance over 120 days under ambient conditions (temperature at 25 ± 4 °C and humidity: 35-45%). Additionally, we fabricated organic photodetectors (OPDs) containing binary additives. The PM6:L8-BO based OPD produced exhibited excellent quantum efficiency with responsivity and detectivity values of 0.62 A W(-) (1) and 2.10 × 10(10) Jones, respectively. Overall, our work highlights the benefits of utilizing binary additive-based active layers in OSCs and OPDs to produce high performance without compromising long-term device stability.