Encapsulation of AIEgens within Metal-Organic Framework toward High-Performance White Light-Emitting Diodes

White light-emitting diodes (WLEDs) have a wide range of applications in display and illumination, however, it is still challenging to achieve efficient solid-state white light-emitting (WLE) materials due to the conventional quenching effect. Herein, a strategy of encapsulating aggregation-induced emission luminogens (AIEgens) into the pores of metal-organic framework (MOF) to achieve high-performance WLED is proposed. Two cationic dyes, 2,3,4,5-tetrakis(4-methoxyphenyl)oxazol-3-ium (MOTPO) and 1-methyl-4-(4-(1,2,2-triphenylvinyl)phenyl)pyridin-1-ium (TPEPy) with bright blue and yellowish green emissions, respectively, are synthesized and successfully incorporated into the pore of anionic MOF ZJU-28. The synergy of AIE characteristics and confinement effect within hybrid material result in an enhanced emission signal in comparison to each of the individual components. The single-phase WLE material with Commission International de L'Eclairage coordinates of (0.35, 0.34) and the quantum efficiency of 64.9% is realized by optimizing the ratio between the two guests, which is almost the best among the reported WLE MOF composites to date. The resulting WLED demonstrates the maximum external quantum efficiency of 12.67% accompanied by the excellent color-rendering index and correlated color temperature of 86 and 4076 K, respectively. Moreover, the WLE flexible film is also achieved. This work will provide new insights and strategies for the design of efficient WLEDs in the future.

Automated summary

This study proposes a strategy for achieving high-performance white light-emitting diodes (WLEDs) by encapsulating aggregation-induced emission luminogens (AIEgens) into the pores of a metal-organic framework (MOF). The optimized WLE material and resulting WLED demonstrate excellent performance.