Full-color afterglows from nonconventional room temperature phosphorescence material realized by triplet-to-singlet Förster-resonance energy transfer

Achieving full-color afterglow emission in nonconventional luminophores devoid of remarkable π-conjugated units is attractive but extremely challenging due to the weak light-absorbance and −emission ability. Here, nonconventional luminophore xylan with superior clusterization-triggered room temperature phosphorescence (RTP) performance was employed to realize full-color afterglows via triplet-to-singlet Förster-resonance energy transfer (TS-FRET). Xylan was first redox-reconstructed to form a denser hydrogen bond network, then redox xylan was further cross-linked with boric acid to afford a highly rigid environment and stabilize the excited state. The light-absorbance and RTP were simultaneously enhanced, which ensured the efficient TS-FRET between xylan derivative and fluorescent emitters. The afterglow emission could be modulated on-demand by TS-FRET, affording the full-color afterglows ranging from blue to red and even white. Xylan RTP materials showed outstanding biodegradability, sustainability, water solubility, and afterglow color tunability, which was useful for advanced anti-counterfeiting and information encryption. This work paves the way for the development of nonconventional RTP materials with full-color afterglows and expands the high-value utilization of xylan.