Chalcogen heteroatom engineering of solid additives with optimized excited-state properties enables the development of high-performance organic solar cells

-DEs), as well as less non-radiative recombination mediated by triplet states. Among them, the optimal performance is attained in the BTD-treated devices, yielding a PCE of up to 19.11%, significantly superior to that of the control devices (18.12%). This study not only expands the library of halogen-free SAs but also highlights the significance of chalcogen heteroatom engineering of SAs in regulating the properties of excited states, suppressing triplet-mediated energy loss as well as advancing the performance of OSCs.