Abstract: As electroluminescent material zinc bis(2-phenyl-8-hydroxyquinolato)[Zn(Q-Ph)₂] was synthesized and characterized by ¹H NMR, UV-Vis and MS measurements. DCJTB[4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran], a highly efficient fluorescent dye, and Zn(Q-Ph)₂ were used to fabricate a kind of novel non-doping organic light-emitting diode with a structure of ITO/NPB{N,N’-Di[(1-naphthalenyl)-N,N’-diphenyl]-(1,1’-biphenyl)-4,4’-diamine}/DCJTB/Zn(Q-Ph)₂/AlQ₃(8-hydroxyquinoline aluminum)/Al. By changing the thickness of ultra-thin layer DCJTB, yellow-light, red-light and orange-light emission from OLEDs were studied. Their luminescent color, electroluminescent mechanism and recombination zone were optimized in this paper. When a 0.5 nm-thick DCJTB was used, a stable red emission was obtained. With a lower turn-on voltage at about 5.5 V, the non-doping OLED showed a ma-ximum brightness of 420 cd/m² and current density of 250 mA/cm² at 25 V.

Key words: Organic light-emitting diode, Non-doping, Recombination zone, DCJTB