Realization of Red-Organic-Light Emitting Diode by Introducing the Double Emitting Zone
JIANG Wen-Long1,2, HOU Jing-Ying1, ZHAO Yi1, LIU Shi-Yong1
1National Laboratory of Integrated Optoelectronics, Jilin University, Changchun 130023
2Electronic Information and Engineering Department, Jilin Normal University, Siping 136000
Realization of Red-Organic-Light Emitting Diode by Introducing the Double Emitting Zone
1National Laboratory of Integrated Optoelectronics, Jilin University, Changchun 130023
2Electronic Information and Engineering Department, Jilin Normal University, Siping 136000
Abstract：A saturated red-organic-light emitting diode (OLED) has been realized by doping an emitting material both in the hole-transporting layer (HTL) and the electron-transporting layer (ETL) to form double emitting zone. The red dopant, 4-(Dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), was doped into the N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB) layer and the tris (8-quinolinolate) aluminum (Alq3) layer, both of which act as the emitting layers. The optimal device, with a structure of ITO/CuPc/NPB/NPB:DCJTB/Alq3:DCJTB/Alq3/LiF/Al, showed good chromaticity coordinates (x = 0.63, y = 0.36) at 8 V. Uniquely, the current efficiency of the device was relatively independent of the drive voltage in a wide range from 8 V to 20 V. That may be helpful to ameliorate the lifetime of the organic electroluminescent devices and to adjust the gray-scale for the future full-color display panel.
2003, Vol. 20 
