Simple construction of deep-red hexaazatrinaphthylene-based thermally activated delayed fluorescence emitters for efficient solution-processed OLEDs with a peak at 692 nm

Two solution-processable deep-red thermally activated delayed fluorescence emitters based on a 5,6,11,12,17,18-hexaazatrinaphthylene acceptor core were developed through a simple and catalyst-free nucleophilic substitution reaction. The solution-processed OLEDs using these emitters achieved a peak external quantum efficiency of 4.8% with the emission peak at 692 nm.