A three-dimensional solid additive suppresses non-radiative recombination loss to boost efficiency and scalability in organic photovoltaics

Abstract

Solid additives have the potential to enhance performance and stability in the field of organic photovoltaics (OPVs). By designing novel additives, we can optimize the crystallinity of polymer donors and phase continuity of small molecule acceptors, thereby reducing defects and charge recombination. Herein, we synthesized five solid additives T1–T5 by combining triphenylamine derivatives with non-fullerene acceptor terminal units. T5, as an additive, showed excellent performance in the PM6:Y6 system. Microstructural characterization revealed that T5 significantly improved molecular stacking and face-on orientation. In situ absorption spectroscopy and exciton and charge carrier behavior tests indicated that T5 facilitated polymer pre-aggregation, resulting in orderly stacking, accelerated exciton dissociation, suppressed charge recombination, and increased charge mobility. With T5 optimization, the system achieved higher electroluminescence efficiency and lower non-radiative recombination loss. The device based on PM6/Y6 optimized by T5 achieved an efficiency of 18.89% while maintaining excellent stability. Furthermore, T5 exhibited remarkable versatility across various binary systems, achieving an efficiency of 19.6% in both PM6/L8-BO and PM6/BTP-eC9 configurations. Its applicability was further demonstrated in large-scale modules, where it attained an active area efficiency of 16.23% in modules with an area of 18.03 cm². These results underscore the potential of 3D solid additives to significantly enhance OPV device efficiency and stability, providing valuable insights for future industrial applications.