Novel Blue Fluorescent Dopants Based on Imidazole-Containing Compound for Organic Electroluminescent Devices

Aminul Islam ； Chia-Chen Tsou ； Hui-Ju Hsu ； Wen-Li Shih ； Charng-Hsing Liu ； Chien-Hong Cheng

《淡江理工學刊》 5卷2期 (2002/06) Pp. 69-80

https://doi.org/10.6180/jase.2002.5.2.01

並列摘要

We report the synthesis of bis-imidazole derivatives [1,4-bis-(2-(4-benzoylphenyl)-5-R-1H-4-imidazolyl)benzene] BSIB-1 (R=phenyl) and BSIB-2 (R=p-tolyl) by a simple one-step reaction of the corresponding substituted tetraone, substituted benzaldehyde and ammonium acetate and the use of these organic compounds as dopant emitters in electroluminescent devices. The physical properties of BSIBs were thoroughly investigated. A general device structure of the devices is ITO/NPB (20 nm)/CBP (20 nm)/BSIB:TPBI (X%, Y nm)/TPBI (20 nm)/Mg:Ag (10:1; 55 nm)/Ag (100 nm), where NPB, CBP and TPBI stand for 4,4'-bis[N-(1-naphthyl)-N-phenyl-amino]-biphenyl, 4,4'-dicarbazolyl-1.1'-biphenyl and 2,2',2”-(1,3,5-phenylene) tris-[1-phenyl-1H-benzimidazole], respectively. Efficient blue-green to blue emission from the devices with luminance ranging from 2500-5000 cd/m^2 was obtained. The efficiencies of the devices and the nature of the emitting color depended substantially on the concentration of the dopant and thickness of the emitting layer. The Förster mechanism is suggested to account for the transfer of energy from host TPBI to the dopant and emission from the dopant.

並列關鍵字

Electroluminescent ； Imidazole Derivatives ； OLED ； Blue-Light Emitting Dopants ； Blue Light