Fluorescent pyrene-imidazole material for deep-blue organic light-emitting devices

Numerous endeavors have been exerted to devise deep-blue light-emitting materials (LEMs) for organic light-emitting devices (OLEDs). Nevertheless, deep-blue light-emitting materials exhibiting high efficiency for simple-structured OLEDs are still scarce. Herein, a donor-acceptor based LEM, 4'-(4, 5-diphenyl-1-(3-(pyren-1-yl)phenyl)-1H-imidazole-2-yl)-N,N-diphenylbiphenyl-4-amine (TPA-PyI) is developed by merging imidazole, triphenyl-amine and pyrene units for OLEDs. TPA-PyI is used as the emitting layer in OLED device, which emits a deep-blue fluorescence at 444 nm. With a current efficiency (CE) of 3.05 cd/A and a power efficiency (PE) of 2.95 lm/W, an EQE of 2.97% is achieved. High thermal-stability is achieved with decomposition-temperature (Td) of 516 °C.