High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes （PHOLEDs）. Efforts have been pai...High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes （PHOLEDs）. Efforts have been paid to find ways to reduce the phosphors＇ concentration and efficiency roll-off of PHOLEDs. In this work, we reported red emission PHOLEDs with low dopant concentration and low efficiency roll-off based on a novel host material 2,4-biscyanophenyl-6-（12-phenylindole[2,3-a]carbazole-ll-yl）-1,3,5-triazine （BCPICT）, with thermally activated delayed fluorescent （TADF） properties. The device with 1.0% dopant concentration displayed a maximum external quantum efficiency of 10.7%. When the dopant concentration was increased to 2.0%, the device displayed a maximum external quantum efficiency of 10.5% and a low efficiency roll-off of 5.7% at 1000 cd/m^2.展开更多
基金supported by the National Natural Science Foundation of China (51525304)the National Key Basic Research and Development Program of China (2015CB655002)
文摘High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes （PHOLEDs）. Efforts have been paid to find ways to reduce the phosphors＇ concentration and efficiency roll-off of PHOLEDs. In this work, we reported red emission PHOLEDs with low dopant concentration and low efficiency roll-off based on a novel host material 2,4-biscyanophenyl-6-（12-phenylindole[2,3-a]carbazole-ll-yl）-1,3,5-triazine （BCPICT）, with thermally activated delayed fluorescent （TADF） properties. The device with 1.0% dopant concentration displayed a maximum external quantum efficiency of 10.7%. When the dopant concentration was increased to 2.0%, the device displayed a maximum external quantum efficiency of 10.5% and a low efficiency roll-off of 5.7% at 1000 cd/m^2.
