Star-configured carbazole as an efficient near-ultraviolet emitter and hole-transporting material for organic light-emitting devices

A novel organic material, 9-methyl-1,3,6,8-tetraphenyl-carbazole (MTPC-Me), for use in organic electroluminescent devices has been developed. This star-configured carbazole gives a strong near-ultraviolet (n-UV) emission (λmax=389nm) with a high emission quantum efficiency of 47% and a narrow full width half maximum of 40nm. Two types of high-performance organic light-emitting devices were obtained using MTPC-Me as a n-UV emitter and hole-transporting material with maximum external quantum efficiency, brightness, and turn-on voltage of 1.2%, 1040cd∕m2, and 3.5V for the former and 1.1%, 18000cd∕m2, and 2.4V for the latter, respectively.