Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (18): 1904-1908.DOI: 10.6023/A12060324 Previous Articles     Next Articles



周亮, 邓瑞平, 郝召民, 宋明星, 张洪杰   

  1. 中国科学院长春应用化学研究所 稀土资源利用国家重点实验室 长春 130022
  • 投稿日期:2012-06-19 发布日期:2012-08-06
  • 通讯作者: 张洪杰
  • 基金资助:

    项目受国家自然科学基金(No. 21071140)和国家自然科学基金创新研究群体项目(No. 20921002)资助.

Efficient White Electroluminescent Device with Stable Emission Spectrum

Zhou Liang, Deng Ruiping, Hao Zhaomin, Song Mingxing, Zhang Hongjie   

  1. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022
  • Received:2012-06-19 Published:2012-08-06
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21071140) and National Natural Science Foundation for Creative Research Group (No. 20921002).

In this work, we report a novel white organic light-emitting device (WOLED) with stable emission spectrum. Red emitter 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) was selected and doped into N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-diphenyl-4,4'-diamine (NPB) layer as hole transport layer and the first light-emitting layer (EML1), which provides blue and red emissions. The widely used green material tris(8-hydroxyquinoline) aluminum (AlQ) was selected as sensitizer of electron injection and doped into NPB layer as the second light-emitting layer (EML2), which provides blue and green emissions. The doping concentrations of DCJTB and AlQ were optimized to be 0.4% and 0.14%, respectively, while the thickness of EML2 was optimized to be 3 nm. Finally, we obtained the pure white organic light-emitting device, which possesses 3.1 V turn-on voltage, 32749 cd/m2 maximum brightness, 8.67 cd/A maximum current efficiency, and 8.78 lm/W maximum power efficiency. More importantly, the use of hole-type host material help to confine the recombination zone of holes and electrons, thus improving the stability of electroluminescent spectrum. With increasing current density, the Commission Internationale de l’Eclairage (CIE) coordinates of this device change from (0.343, 0.342) to (0.328, 0.336).

Key words: electroluminescence, fluorescent material, injection of electrons, recombination of carriers, luminescent efficiency