High‐Efficiency WOLEDs with High Color‐Rendering Index based on a Chromaticity‐Adjustable Yellow Thermally Activated Delayed Fluorescence Emitter

Abstract

A chromaticity-adjustable yellow thermally activated delayed fluorescence (TADF) material, PXZDSO2 as a triplet harvester provides a rational device concept, giving two-color and three-color pure organic white organic light-emitting diodes (WOLEDs) with unprecedented color-rendering index of 95 and external quantum efficiency of 19.2%.