物理化学学报 >> 2007, Vol. 23 >> Issue (10): 1493-1497.doi: 10.1016/S1872-1508(07)60074-6

研究论文 上一篇    下一篇

高效白色磷光有机电致发光器件

李璐; 于军胜; 王军; 娄双玲; 蒋亚东; 李伟   

  1. 电子科技大学光电信息学院, 电子薄膜与集成器件国家重点实验室, 成都 610054
  • 收稿日期:2007-04-05 修回日期:2007-06-19 发布日期:2007-10-01
  • 通讯作者: 于军胜;蒋亚东 E-mail:jsyu@uestc.edu.cn;jiangyd@uestc.edu.cn

High-efficiency of White Phosphorescent Organic Light-Emitting Diodes

LI Lu; YU Jun-Sheng; WANG Jun; LOU Shuang-Ling; JIANG Ya-Dong; LI Wei   

  1. State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, P. R. China
  • Received:2007-04-05 Revised:2007-06-19 Published:2007-10-01
  • Contact: YU Jun-Sheng;JIANG Ya-Dong E-mail:jsyu@uestc.edu.cn;jiangyd@uestc.edu.cn

摘要: 采用真空热蒸镀方法以4,4'-bis (carbazol-9-yl) biphenyl (CBP)为主体材料、以bis[2-(4-tert-butylphenyl) benzothiazolato-N,C2] iridium (acetylacetonate) [(t-bt)2Ir(acac)]磷光染料为掺杂剂构成黄色发光层, 制备了高效白光的有机电致发光器件(OLEDs). OLEDs的器件结构为indiumtin oxide (ITO)/N,N’-bis-(1-naphthyl)-N,N’-biphenyl-1,1’-biphenyl-4,4’-diamine (NPB)/CBP: (t-bt)2Ir (acac)/NPB/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/8-hydroxy quinoline aluminum(Alq3)/Mg:Ag, 从ITO阳极开始的第一层NPB为空穴传输层, 第二层超薄的NPB为蓝色发光层, BCP为空穴阻挡层和激子阻挡层, Alq3为电子传输层. 结果表明, 器件电压在3 V启亮, 在16.5 V时, 器件的最高亮度达到15460 cd·m-2; 在4 V时, 器件达到最大流明效率为7.5 lm·W-1, 器件启亮后所发出的白光光谱在低电压时随电压变化有稍微的移动, 但是都在白光范围内变化. 在电压达到8 V后Commission Internationale I’Eclairage(国际照明委员会) (CIE)色坐标为(0.33, 0.32), 并且光谱及色坐标稳定, 不随电压变化而改变, 与最佳的白光坐标(0.33, 0.33)几乎重合. 同时, 从机理上解释了光谱移动和效率衰减的原因, 并探讨了载流子陷阱和能量传递的关系.

关键词: 有机电致发光, 白色发光, 磷光, 铱配合物, 载流子陷阱, 能量传递

Abstract: High-efficiency white organic light-emitting devices (WOLEDs) based on phosphorescent dye bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2’]iridium (acetylacetonate) [(t-bt)2Ir (acac)] doped 4,4’-bis (carbazol-9-yl) biphenyl (CBP) as a yellow emitting layer were fabricated. The structure of the devices is indium tin oxide (ITO)/N,N’-bis-(1-naphthyl)-N,N’-biphenyl-1,1’-biphenyl-4,4’-diamine (NPB)/CBP: (t-bt)2Ir(acac)/NPB/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/8-hydroxyquinoline aluminum(Alq3)/Mg:Ag, and the second NPB layer fromthe anode was used as a blue fluorescent emitter and the first NPB layer was used as a hole transporting layer, the BCP and Alq3 were used as hole blocking and electron transporting layers, respectively. The turn-on voltage of the device was 3 V with a maximumluminance of 15460 cd·m-2 at 16.5 V and maximumluminance efficiency of 7.5 lm·W-1 at 4 V, respectively. The Commission Internationale de I’Eclairage (CIE) coordinates located at (0.33, 0.32) remained stable at the driving voltage higher than 8 V, which is almost consistent with the optimum white CIE of (0.33, 0.33). The purity of white light could be adjusted by doping concentration. The effect of charge carrier trapping and energy transfer on the device performance were also discussed.

Key words: Organic light-emitting diodes, White light, Phosphorescence, Iridium complex, Carrier trapping, Energy transfer

MSC2000: 

  • O644