A new blue-emitting benzothiazole derivative for organic electroluminescent devices

A benzothiazole derivative (BT) with a high fluorescence quantum yield (phi (f) = 0.92) was synthesized and first used as a dopant in a blue organic electroluminescent device. TPD is N,N ' -bis(3-methylphenyl)-N,N ' -diphenyl-1,1 ' -biphenyl-4,4 ' -diamine and was used as a hole-transporting material; DPBI is a dimer of N-arylbenzimidazole and was used as an electron-transporting material as well as the host for the blue-emitting dopant, BT. A device with a structure of ITO/TPD/DPBI-2% BT/DPBI/Mg-Ag was fabricated. The devices showed electroluminescence with an emission peak around 475 mn. A luminance of 1260 cd m(-2) was achieved at a current density of 400 mA cm(-2). The current efficiency of this device is about 0.50 cd A(-1) at 5 V. (C) 2001 Elsevier Science B.V. All rights reserved.