Chiral-Template-Free Color-Tunable Circularly Polarized Long Afterglow from Carbon Dots with Aggregation-Induced Emission and High Dissymmetry Factor

Circularly polarized long afterglow (CPLA) materials feature an extended emission lifetime and unique chiroptical properties. However, current systems suffer from limited color tunability and low luminescence dissymmetry factors (glum). Using chiral cellulose nanocrystals, dithiosalicylic acid, and calcium chloride as precursors, we synthesized carbon dots (CDs) with aggregation-induced emission and high glum values without using any external chiral template. The CDs emit blue in the dispersed state and red in the aggregated state, with the mechanism shifting from carbon-core- to surface-state-dominated emission. When embedded in a poly(vinyl alcohol) film, the CDs exhibited green CPLA. A hierarchical chiral light-harvesting system enables simultaneous chirality and energy transfer, producing multicolor CPL with high glum. This work provides a versatile strategy for tunable circularly-polarized-luminescence-active materials for dynamic anticounterfeiting and multidimensional information encryption.