Enhanced Photoactivated Circularly Polarized Afterglow with High Dissymmetry Factor and Tunable Emission

Abstract

Photoactivated circularly polarized afterglow (CPA) exhibits broad application prospects in various optoelectronic areas due to its multidimensional emission characteristics, including wavelengths, lifetimes, and chirality. Achieving photoactivated CPA with extremely high dissymmetry factor (g_lum) values is highly desired but considerably challenging. This work reports a bilayer assembly (R/S‐CLC‐TPB) integrating a TPB@PMMA thin film with the selective reflection of cholesteric liquid crystals. Initially, R/S‐CLC‐TPB exhibits no afterglow emission, while following 1 min of UV irradiation, it achieves an noticeable CPA with a long emission lifetime of 125 ms and a high g_lum value of up to 1.6. This enhancement can be attributed to the oxygen consumption properties under UV irradiation, subsequently minimizing the loss of triplet exciton. Furthermore, by employing a triplet‐singlet Förster resonance energy transfer (TS‐FRET) strategy from photoactivated organic persistent room‐temperature phosphorescence donor to fluorescent dye acceptor, the afterglow color is successfully modulated from green to orange. Ultimately, these materials demonstrate promising capabilities for advanced multi‐level information encryption by utilizing their tunable afterglow color, long emission lifetimes, and high g_lum values to create multiple encryption layers that can be selectively accessed and decoded based on photoactivation and chiroptical properties.