Red Phosphorescence at Elevated Temperatures Enabled by Dexter Energy Transfer in Polyaromatic Hydrocarbon-Xanthone Systems.

Organic materials with red persistent phosphorescence hold immense promise for biotechnology due to their excellent tissue permeability and high signal-to-background ratios. However, inefficient spin-orbit coupling, high triplet susceptibility, and narrow energy gapspromoted nonradiative deactivations, pose a formidable obstacle to achieving efficient red phosphorescence. This study addresses these challenges by introducing xanthone (Xan)-based host-guest systems.

Efficient intersystem crossing and tunable ultralong organic room-temperature phosphorescence via doping polyvinylpyrrolidone with polyaromatic hydrocarbons.

Polymer-based pure organic room-temperature phosphorescent materials have tremendous advantages in applications owing to their low cost, vast resources, and easy processability. However, designing polymer-based room-temperature phosphorescent materials with large Stokes shifts as key requirements in biocompatibility and environmental-friendly performance is still challenging. By generating charge transfer states as the gangplank from singlet excited states to triplet states in doped organic molecules, we find a host molecule (pyrrolidone) that affords charge transfer with doped guest molecules, and excellent polymer-based organic room-temperature phosphorescent materials can be easily fabricated when polymerizing the host molecule.