Realizing High Efficiency and High Color Quality for All‐Fluorescence White Organic Light‐Emitting Diodes by Interlayer‐Sensitizing Configuration with Electron‐Capturing Agent

Abstract As a promising next‐generation lighting technology, all‐fluorescence white organic light‐emitting diodes (WOLEDs) have advanced rapidly but still face the formidable challenge of achieving high efficiencies and high color quality simultaneously. Herein, an interlayer sensitization strategy assisted by electron‐capturing agent with thermally activated delayed fluorescence (TADF) is proposed for the fabrication of high‐performance all‐fluorescence WOLEDs. The proof‐of‐concept three‐color devices with an interlayer‐sensitizing configuration are designed, and a low concentration of TADF electron‐capturing agent is codoped with a red conventional fluorescence (CF) emitter to reduce exciton loss. The major energy transfer from TADF sensitizing layer to red CF emitter combined with the supplementary energy transfer from TADF electron‐capturing agent to CF emitter can successfully increase exciton utilization. The synergistic effect endows the three‐color all‐fluorescence WOLEDs with high efficiencies, high color quality, and improved efficiency stability and operational stability, simultaneously. The resultant WOLEDs successfully attain remarkable external quantum efficiency of 31.0%, outstanding color rendering index of 93 and long operational lifetime. The record‐beating comprehensive performances of these WOLEDs strongly demonstrate the great potential of the proposed strategy for the exploration of high‐performance all‐fluorescence WOLEDs.