Highly Performances Blue Thermally Activated Delayed Fluorescence Devices and Efficient Host-Emitter Interactions

The influence of host-emitter interactions on electroluminescent (EL) performances of thermally activated delayed fluorescence (TADF) emitter had not explored in detail. In this study, by doping DMTDAc into host materials with different polarity and energy levels as emitting layer, we demonstrated that the choice of host can be able to greatly impact on the EL performances. Finally, we found the variation of device performances was mainly dominated by energy transfer and charge trapping progresses in emitting layers, and stable blue TADF device with maximum efficiencies and brightness of 23.74 cd/A, 24.05 lm/W, 21.9% and 5695 cd/m², was obtained. (paper)