A New Starburst DCM-Type Red-Light-Emitting Material for Electroluminescence Applications: Physical and Electroluminescent Characteristics of TNGT

A new starburst DCM derivative-Tris(4-(2-(N-butyl-1,8-naphthalimide)ethynyl) phenyl)amine (TNGT)- has been designed and synthesized for application as red-light emitter in organic light-emitting diodes (OLEDs). Photoluminescence and electroluminescence measurements show that it exhibits a greatly restricted concentration-quenching effect compared to DCM1 (4-(dicyanomethylene)-2-methyl-6-[p-(N,N-dimethylamino)-styryl]-4H-pyran). By doping TNGT in a PVK emissive layer, the electroluminescence device with the configuration ITO/PVK: TNGT (20 wt. -%) (70 nm)/ BCP(15 nm) /Alq₃ (15 nm)/LiF (0.3 nm)/Al (150 nm) exhibits a turn-on voltage of 6.5 V, a maximum luminance of 6600 cd/m², a maximum efficiency of 4.57cd/A (at 420 cd/m²) and chromaticity coordinates of (0.59, 0.40).