Luminescent carbene–copper( i )–amide polymers for efficient host-free solution-processed OLEDs

• Published in: Chemical science (Cambridge) Vol. 15; no. 29; pp. 11382 - 11390
• Main Authors: Tan, Yao, Ying, Ao, Xie, Jianlong, Xie, Guohua, Gong, Shaolong
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 24.07.2024; The Royal Society of Chemistry
• Subjects: Carbenes; Chemistry; Coordination compounds; Copper; Emission; Emitters; Organic light emitting diodes; Phosphorescence; Photoluminescence; Polymers; Polystyrene resins; Quantum efficiency
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d4sc01865f

Luminescent metallopolymers have attracted broad interest in the fields of healthcare and organic electronics. However, polymeric emitters based on earth-abundant metal complexes are scarce. Here, two series of Cu( i ) polymers, PMAC-x and PCAAC-x ( x = 1–3) have been developed using two kinds of Cu( i )-based carbene–metal–amide (CMA) complexes as side-chain emitter units to combine with a nonconjugated polystyrene backbone. These Cu( i ) polymers emit via distinct thermally activated delayed fluorescence or dominant phosphorescence, inherited from the grafted Cu( i )-based CMA units. Particularly, the PMAC-x polymers exhibit high photoluminescence quantum efficiencies of up to 0.78, short emission lifetimes of down to 0.66 μs, and fast radiative rates of up to 10 6 s −1 in neat films. Thanks to the good encapsulation effect of the polystyrene backbone, these Cu( i ) polymers not only demonstrate favorable moisture stability but also show significant aggregation-induced emission. The resultant host-free solution-processed organic light-emitting diodes (OLEDs) achieve outstanding electroluminescence performance with a record external quantum efficiency of 13.8% at a practical luminance of ∼100 nits, representing state-of-the-art device efficiency for metallopolymer-based OLEDs. This work not only presents the first example of CMA polymers but also provides the future direction of polymeric emitters from earth-abundant metal complexes for the OLED application.