Achieving dual-mode long-persistence afterglow through an aromatic furan organic host–guest system†

Pure organic long-persistence luminescence has recently garnered significant attention due to its diverse potential applications. Nonetheless, the attainment of pure organic dual-mode long-persistence afterglow with high efficiency remains a significant challenge. Herein, we report the successful realization of high-efficiency, color-tunable dual-mode room-temperature phosphorescence (RTP) along with thermally activated delayed fluorescence (TADF) of approximately 50 ms, utilizing an aromatic furan organic host–guest system. Our investigation into this system reveals two key findings: (1) the heavy-atom effect of the host and guest molecules plays distinct roles in modulating the efficiency of the intersystem crossing (ISC) and reverse intersystem crossing (RISC) processes; and (2) the dual-mode long-persistence luminescence can be effectively adjusted by manipulating the energy gap between the excited triplet states of host and guest molecules. Additionally, we demonstrated the capability for color display utilizing this host–guest system through inkjet printing.