Chiral Polymer‐Organic Molecule Composite with Circularly Polarized Thermally Activated Delayed Fluorescence and Room‐Temperature Phosphorescence by Bridging Effect of Hydrogen Bond

• Published in: Advanced functional materials 2024-11, Vol.34 (45), p.n/a
• Main Authors: Chen, Ruilian, Feng, Rui, Huang, Zhenjie, Feng, Dengchong, Long, YuBo, Zhang, Jiawen, Yang, Yuzhao, Ma, Zetong, Yuan, Zhongke, Lu, Shaolin, Zhao, Zujin, Chen, Xudong
• Format: Article
• Language: English
• Subjects: cellulose nanocrystals; Chemical bonds; chiral photonic film; Circular polarization; circularly polarized room‐temperature phosphorescence; circularly polarized thermally activated delayed fluorescence; Emitters; Excitons; Fluorescence; Hydrogen bonding; Hydrogen bonds; long afterglow; Luminescence; Optical properties; Organic chemistry; Phosphorescence; Photoluminescence; Photonic band gaps; Photonic crystals; Polymer films; Polymers; Polyvinyl alcohol
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202404602

Circularly polarized luminescence is essential to chiral and photonic science, but achieving circularly polarized thermally activated delayed fluorescence (CP‐TADF) and circularly polarized room‐temperature phosphorescence (CP‐RTP) simultaneously remains a great challenge. This is because it is difficult to satisfy simultaneously the stable triplet exciton, appropriate energy gap, and the regular chiral environment. Herein, a simple strategy is reported to construct a persistent photoluminescent system, which can achieve TADF and RTP simultaneously by suppressing the non‐radiative transition decay of the triplet exciton through intermolecular hydrogen bonding between acridine flavin (AF) and rigid polymer network. The persistent photoluminescent composite exhibited ultra‐long lifetimes and high quantum yields. Then, a rarely multi‐circularly polarized photoluminescence system containing CP‐TADF and CP‐RTP is constructed by the co‐assembly of cellulose nanocrystals, polyvinyl alcohol, and AF. By utilizing the cholesteric structure, photonic band gap of chiral photonic crystals, and the stabilization mechanism of triplet exciton by intermolecular hydrogen bonding between the light emitter and rigid polymer, chiral photoluminescent films exhibited rare optical properties simultaneously: multi‐circularly polarized photoluminescence emission, high and tunable dissymmetric factor, significant quantum yield, and ultralong lifetimes, which are not reported before and broaden the perspective for multi‐circularly polarized luminescence. Evaporation‐induced self‐assembly of cellulose nanocrystals, polyvinyl alcohol, and light emitter enables high‐performance dual‐persistent photoluminescence simultaneously with various circularly polarized effects, including thermally activated delayed fluorescence and room temperature phosphorescence. This approach, incorporating chiral templates, rigid polymers, and luminescent materials, demonstrates the universality of achieving circularly polarized photoluminescence through hydrogen‐bonding bridging.