Ambient White Light Afterglow Emission Based on Triplet-to-Singlet Forster Resonance Energy Transfer

Compared with fluorescent materials, metal-free organic environmental afterglow materials, with larger Stokes shifts, longer lifetimes, higher S/N ratios, and sensitivities, present potential in new applications. However, achieving air stability and long lifetime organic afterglow systems with tunable emission color still remains a challenge. Herein, we have designed and synthesized luminescent copolymers exhibiting afterglow emission with tun-ability including white-light afterglow with considerable quantum yield [Commission Internationale de l'Eclairage (CIE) coordinates (0.32, 0.33), Phi(P) = 11%] in the amorphous state through the rarely reported triplet-to-singlet Forster resonance energy transfer (TS-FET). Also, they can emit different colors under UV light, including white-light [CIE coordinates (0.31, 0.33), Phi(Pl) = 27%]. This strategy was achieved by copolymerizing two simple-structured single-benzene-based compounds with acrylamide (AM) in different ratios. In addition, these materials can also be employed as a safety ink for paper paving the way for long lifetime luminescent material applications. [GRAPHICS] .