Efficient exciton regulation for high-performance hybrid white organic light-emitting diodes with superior efficiency/CRI/color stability based on blue aggregation-induced emission fluorophor

Fluorescent/phosphorescent hybrid white organic light-emitting diodes (WOLEDs) combining blue aggregation-induced emission (AIE) fluorophors with efficient yellow (or green/red) phosphors have attracted more attention in applications of full-color display and solid-state lighting. However, it is still a major challenge for hybrid WOLEDs based on AIE-active fluorophors to simultaneously realize high efficiency, high color rendering index (CRI), good color stability and low efficiency roll-off. Here, a sky-blue AIE fluorophor as the neat emitter has been successfully applied to high-performance blue OLED and two-/three-color hybrid WOLEDs. The blue device with a high exciton utilization efficiency of 47.4%–71.1% realizes the external quantum efficiencies (EQEs) of 6.3 and 5.5% at 1000 and 5000 cd m−2. By accurately managing the arrangement of emissive layers, Three-color WOLED without the damage of deep-blue light not only realizes high efficiencies of 41.6 cd A−1 and 46.6 lm W−1, but also shows a high CRI over 80 and good color stability with the Commission Internationale de L'Eclairage (CIE) coordinates changing from (0.432, 0.480) to (0.418, 0.488) when the driving voltage increases from 4 to 7 V, meeting the requirement for energy-saving and healthy lighting source. Such excellent EL performance is really rare in the no deep-blue light damage, high CRI and good color stability hybrid WOLEDs based on AIE-active fluorophor. © 2021