中国物理B ›› 2011, Vol. 20 ›› Issue (10): 107803-107803.doi: 10.1088/1674-1056/20/10/107803

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Improving efficiency of organic light-emitting devices by optimizing the LiF interlayer in the hole transport layer

焦志强, 吴晓明, 华玉林, 董木森, 苏跃举, 申利莹, 印寿根   

  1. School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China; Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin 300384, China; Tianjin Key Laboratory for Photoelectric Mat
  • 收稿日期:2011-05-04 修回日期:2011-06-02 出版日期:2011-10-15 发布日期:2011-10-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60906022 and 60876046) and the Tianjin Natural Science Foundation of China (Grant No. 10JCYBJC01100).

Improving efficiency of organic light-emitting devices by optimizing the LiF interlayer in the hole transport layer

Jiao Zhi-Qiang(焦志强)a)b)c), Wu Xiao-Ming(吴晓明)a)b)c), Hua Yu-Lin(华玉林)a)b)c), Dong Mu-Sen(董木森)a)b)c), Su Yue-Ju(苏跃举)a)b)c), Shen Li-Ying(申利莹)a)b)c), and Yin Shou-Gen(印寿根)a)b)c)   

  1. School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China; Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin 300384, China; c Tianjin Key Laboratory for Photoelectric MatTianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin 300384, China
  • Received:2011-05-04 Revised:2011-06-02 Online:2011-10-15 Published:2011-10-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60906022 and 60876046) and the Tianjin Natural Science Foundation of China (Grant No. 10JCYBJC01100).

摘要: The efficiency of organic light-emitting devices (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-N,1'-biphenyl-4,4'-diamine (NPB) (the hole transport layer) and tris(8-hydroxyquinoline) aluminum (Alq3) (both emission and electron transport layers) is improved remarkably by inserting a LiF interlayer into the hole transport layer. This thin LiF interlayer can effectively influence electrical performance and significantly improve the current efficiency of the device. A device with an optimum LiF layer thickness at the optimum position in NPB exhibits a maximum current efficiency of 5.96 cd/A at 215.79 mA/cm2, which is about 86% higher than that of an ordinary device (without a LiF interlayer, 3.2 cd/A). An explanation can be put forward that LiF in the NPB layer can block holes and balance the recombination of holes and electrons. The results may provide some valuable references for improving OLED current efficiency.

关键词: organic light-emitting devices, LiF, interlayer, efficiency

Abstract: The efficiency of organic light-emitting devices (OLEDs) based on N,N'-bis(1-naphthyl)-N,N'-diphenyl-N,1'-biphenyl-4,4'-diamine (NPB) (the hole transport layer) and tris(8-hydroxyquinoline) aluminum (Alq3) (both emission and electron transport layers) is improved remarkably by inserting a LiF interlayer into the hole transport layer. This thin LiF interlayer can effectively influence electrical performance and significantly improve the current efficiency of the device. A device with an optimum LiF layer thickness at the optimum position in NPB exhibits a maximum current efficiency of 5.96 cd/A at 215.79 mA/cm2, which is about 86% higher than that of an ordinary device (without a LiF interlayer, 3.2 cd/A). An explanation can be put forward that LiF in the NPB layer can block holes and balance the recombination of holes and electrons. The results may provide some valuable references for improving OLED current efficiency.

Key words: organic light-emitting devices, LiF, interlayer, efficiency

中图分类号:  (Electroluminescence)

  • 78.60.Fi
73.61.Ng (Insulators) 73.61.Ph (Polymers; organic compounds)