Boosting Organic Long Persistent Luminescence by Enhancing Charge Separation Processes in Three‐Component Systems

Abstract Organic long persistent luminescence (OLPL) materials feature power law emission decay and minutes‐/hours‐long afterglow durations because of retarded charge recombination. Unlike conventional room‐temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) afterglow, the emergence of OLPL must include a charge separation process in its photophysical mechanism; consequently, the reported OLPL examples are much fewer than conventional afterglow materials. The incorporation of an electron donor or acceptor is conceived to interact with the long‐lived excited state in conventional afterglow system, aiming to induce charge separation. Here, the study first builds two‐component RTP/TADF afterglow systems composed of difluoroboron β‐diketonate (BF 2 bdk) dopants and organic crystalline matrices, and then introduces an electron‐donating component into the two‐component BF 2 bdk‐matrix systems to enable the charge separation processes. The resultant three‐component materials exhibit visible‐light‐excitable OLPL afterglow lasting for several hours under ambient condition. Leveraging the efficient harvesting of singlet/triplet excitons by BF 2 bdk and the protective environment provided by the crystalline matrix, the three‐component materials exhibit an estimated OLPL efficiency of ≈10% and display OLPL brightness comparable to inorganic Sr 2 Al 14 O 25 /Eu 2+ , Dy 3+ materials. Furthermore, the obtained OLPL materials show promising applications in afterglow displays and information storage, marking a significant step toward practical implementations of organic afterglow materials.