›› 2015, Vol. 24 ›› Issue (4): 47203-047203.doi: 10.1088/1674-1056/24/4/047203

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Improvement of mobility edge model by using new density of states with exponential tail for organic diode

Muhammad Ammar Khan, 孙久勋   

  1. School of Physical Electronics, University of Electronic Science and Technology, Chengdu 610054, China
  • 收稿日期:2014-08-26 修回日期:2014-11-04 出版日期:2015-04-05 发布日期:2015-04-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 31470822).

Improvement of mobility edge model by using new density of states with exponential tail for organic diode

Muhammad Ammar Khan, Sun Jiu-Xun (孙久勋)   

  1. School of Physical Electronics, University of Electronic Science and Technology, Chengdu 610054, China
  • Received:2014-08-26 Revised:2014-11-04 Online:2015-04-05 Published:2015-04-05
  • Contact: Sun Jiu-Xun E-mail:sjx@uestc.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 31470822).

摘要: The mobility edge (ME) model with single Gaussian density of states (DOS) is simplified based on the recent experimental results about the Einstein relationship. The free holes are treated as being non-degenerate, and the trapped holes are dealt with as being degenerate. This enables the integral for the trapped holes to be easily realized in a program. The J-V curves are obtained through solving drift-diffusion equations. When this model is applied to four organic diodes, an obvious deviation between theoretical curves and experimental data is observed. In order to solve this problem, a new DOS with exponential tail is proposed. The results show that the consistence between J-V curves and experimental data based on a new DOS is far better than that based on the Gaussian DOS. The variation of extracted mobility with temperature can be well described by the Arrhenius relationship.

关键词: organic diode, potential barriers, Einstein relationship

Abstract: The mobility edge (ME) model with single Gaussian density of states (DOS) is simplified based on the recent experimental results about the Einstein relationship. The free holes are treated as being non-degenerate, and the trapped holes are dealt with as being degenerate. This enables the integral for the trapped holes to be easily realized in a program. The J-V curves are obtained through solving drift-diffusion equations. When this model is applied to four organic diodes, an obvious deviation between theoretical curves and experimental data is observed. In order to solve this problem, a new DOS with exponential tail is proposed. The results show that the consistence between J-V curves and experimental data based on a new DOS is far better than that based on the Gaussian DOS. The variation of extracted mobility with temperature can be well described by the Arrhenius relationship.

Key words: organic diode, potential barriers, Einstein relationship

中图分类号:  (Polymers; organic compounds (including organic semiconductors))

  • 72.80.Le
73.40.-c (Electronic transport in interface structures) 73.40.Cg (Contact resistance, contact potential) 73.61.Ph (Polymers; organic compounds)