中国物理B ›› 2002, Vol. 11 ›› Issue (10): 1076-1081.doi: 10.1088/1009-1963/11/10/320

• • 上一篇    

Numerical analysis of the mechanism of carrier transport in organic light-emitting devices

张旭1, 台夕市2, 彭应全3, 张福甲3, 何锡源3   

  1. (1)Department of Physics, Gansu Institute of Education, Lanzhou 730030, China; (2)School of Chemistry and Chemical Industry, Lanzhou University, Lanzhou 730000, China; (3)School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
  • 收稿日期:2002-04-08 修回日期:2002-06-10 出版日期:2002-10-12 发布日期:2005-06-12
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 60076023).

Numerical analysis of the mechanism of carrier transport in organic light-emitting devices

Peng Ying-Quan (彭应全)a, Zhang Fu-Jia (张福甲)a, Tai Xi-Shi (台夕市)b, He Xi-Yuan (何锡源)a, Zhang Xu (张旭)c   

  1. a School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China; b School of Chemistry and Chemical Industry, Lanzhou University, Lanzhou 730000, China; c Department of Physics, Gansu Institute of Education, Lanzhou 730030, China
  • Received:2002-04-08 Revised:2002-06-10 Online:2002-10-12 Published:2005-06-12
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 60076023).

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摘要： The mechanism of carrier transport in organic light-emitting devices is numerically studied, on the basis of trapped-charge-limited conduction with an exponential trap distribution. The spatial distributions of the electrical potential, field and carrier density in the organic layer are calculated and analysed. Most carriers are distributed near the two electrodes, only a few of them are distributed over the remaining part of the organic layer. The carriers are accumulated near the electrodes, and the remaining region is almost exhausted of carriers. When the characteristic energy of trap distribution is greater than 0.3 eV, it leads to a reduction of current density. In order to improve the device efficiency, organic materials with minor traps and low characteristic energy should be chosen. The diffusion current is the dominant component near the injection electrode, whereas the drift current dominates the remaining region of the organic layer.

Abstract: The mechanism of carrier transport in organic light-emitting devices is numerically studied, on the basis of trapped-charge-limited conduction with an exponential trap distribution. The spatial distributions of the electrical potential, field and carrier density in the organic layer are calculated and analysed. Most carriers are distributed near the two electrodes, only a few of them are distributed over the remaining part of the organic layer. The carriers are accumulated near the electrodes, and the remaining region is almost exhausted of carriers. When the characteristic energy of trap distribution is greater than 0.3 eV, it leads to a reduction of current density. In order to improve the device efficiency, organic materials with minor traps and low characteristic energy should be chosen. The diffusion current is the dominant component near the injection electrode, whereas the drift current dominates the remaining region of the organic layer.

Key words: organic light-emitting device, carrier transport, numerical analysis

中图分类号:  (Light-emitting devices)

  • 85.60.Jb
72.20.Jv (Charge carriers: generation, recombination, lifetime, and trapping) 72.80.Le (Polymers; organic compounds (including organic semiconductors)) 85.30.De (Semiconductor-device characterization, design, and modeling)