Highly efficient solution-processed blue organic light-emitting diodes based on thermally activated delayed fluorescence emitters with spiroacridine donor

High-efficiency solution-processed blue organic light-emitting diodes (OLEDs) were developed using two thermally activated delayed fluorescence (TADF) aromatic molecules, 10-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2,5-dimethylphenyl)-10H-spiro[acridine-9,9′-fluorene] (TXSA) and 10-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-methylphenyl)-10H-spiro[acridine-9,9′-fluorene] (TTSA), composed of spiroacridine donor and triazine acceptor units. As a result, the blue devices based on two novel TADF molecules exhibited remarkable electroluminescence with a high quantum efficiency of 14.94% and current efficiency of 29.29 cd/A by optimization of emitter doping concentration and properties of the electron transporting layer. Our results demonstrate that TXSA and TTSA TADF molecules are prospective materials to fabricate high-performance solution-processed blue OLEDs with a simple device structure.