Dual-mode Förster resonance energy transfer for color-tunable and stimulus-responsive organic afterglow
Achieving flexible polymer-based organic afterglow materials with color-tunable and stimulus-responsive capabilities is significant in diverse optoelectronic fields, especially in next-generation wearable full-color display applications, yet remains a great challenge. Here, we report polymer-based dual-mode afterglow systems that realize long-lived color-tunable afterglow with full-color gamut of blue, green, orange, red, and even white-light emissions with ultralong lifetimes up to 2.42 s. This unique performance is enabled by a universal strategy of dual-mode afterglow-assisted Förster resonance energy transfer (FRET) that utilizes seconds-long dual-mode afterglow materials as energy donors and permits efficient synchronous transfer of singlet and triplet excitons from energy donors to the fluorescent dye acceptors. More impressively, the dual-mode afterglow-assisted FRET efficiency reaches up to 99%, with the lifetime of the energy acceptor reaching 1.55 s. Associated with the abundant hydrogen-bonding interactions within the polymer system, the doped afterglow films exhibit water/thermal stimulus responsiveness and recyclability. Furthermore, these full-color dual-mode afterglow materials are employed for multicolor screen-printing, optical anti-counterfeiting, and high-level information encryption, demonstrating considerable application potential in advanced anti-counterfeiting technologies.