A Promising Multifunctional Deep‐Blue Fluorophor for High‐Performance Monochromatic and Hybrid White OLEDs with Superior Efficiency/Color Stability and Low Efficiency Roll‐Off

High-performance deep-blue fluorescent materials matching the required Commission Internationale de l'Eclairage y coordinate value (CIEy) of < 0.08 are much-needed in organic light-emitting diodes (OLEDs) for realizing the perfect application of full-color displays. However, deep-blue fluorophors commonly show unsatisfactory performance due to the intrinsic large bandgap characteristic. Here, the deep-blue nondoped OLED with the good CIE coordinates of (0.15, 0.07) and external quantum efficiency (EQE) of ≈9% is achieved based on a multifunctional and efficient anthracene-based fluorophor (2M-ph-3CzAnBzt). Using it as a host, the sky-blue fluorescent OLED realizes the maximum EQE of 9.50%, and keeps as high as 9.27% and 8.56% at 1000 and 5000 cd m−2. More surprisingly, high-performance hybrid white OLEDs (WOLEDs) with good color stability and low roll-off are achieved by using it as the blue emitter. Two-color WOLED shows the forward-viewing efficiencies of 20.46%, and 76.80 lm W−1. The three-color WOLED emitting a candlelight with the color rendering index of ≥ 82 realizes the maximum EQE of 21.49% and remains 20.80% at 1000 cd m−2. Such superior electroluminescence performance achieved in these OLEDs ranks among the highest values based on deep-blue fluorophors with CIEy < 0.08.