V-shaped triazine host featuring intramolecular non-covalent interaction for highly efficient white electroluminescent devices

The exploration of host materials with simultaneously excellent electrical properties and high triplet energy levels is highly essential but challenging in the fields of blue and white phosphorescence (Ph) and thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, the symmetric V-shaped triazine host of DCzT in D-A-D molecular configuration featuring non-covalent intramolecular interactions (NCIs) was designed and synthesized through the replacement of phenyl core of highly twisted blue host of mCP by the acceptor unit of 2,4-dichloro-1,3,5-triazine. By means of the NCIs, DCzT demonstrates a relatively closed plane, thus boosting ordered molecular packing arrangement for the formation of carrier transport channel to acquire enhanced and balanced electrical performance at a high triplet energy level. Excitingly, highly efficient white TADF OLEDs was achieved displaying maximum luminance of 12000 cd m−2 and external quantum, current and power efficiencies of 23.2%, 66.9 cd A-1 and 70.0 lm W−1, respectively. This work highlights that the NCI affords a simple and intelligent way to regulate the electrical attributes of organic optoelectronic materials.