中国物理B ›› 2012, Vol. 21 ›› Issue (5): 57110-057110.doi: 10.1088/1674-1056/21/5/057110

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

The effect of spin-orbit coupling on magnetoresistance in nonmagnetic organic semiconductors

赵俊卿,丁猛,张天佑,张宁玉,庞岩涛,季燕菊,陈莹,王凤翔,付刚   

  1. School of Science, Shandong Jianzhu University, Jinan 250101, China
  • 收稿日期:2011-09-03 修回日期:2012-04-27 出版日期:2012-04-01 发布日期:2012-04-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11005070), and the Research Planning Project of Ministry of Housing and Urban-Rural Development, China (Grant No. 2010-K4-15).

The effect of spin-orbit coupling on magnetoresistance in nonmagnetic organic semiconductors

Zhao Jun-Qing(赵俊卿)†, Ding Meng(丁猛), Zhang Tian-You(张天佑), Zhang Ning-Yu(张宁玉), Pang Yan-Tao(庞岩涛), Ji Yan-Ju(季燕菊), Chen Ying(陈莹), Wang Feng-Xiang(王凤翔), and Fu Gang(付刚)   

  1. School of Science, Shandong Jianzhu University, Jinan 250101, China
  • Received:2011-09-03 Revised:2012-04-27 Online:2012-04-01 Published:2012-04-01
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11005070), and the Research Planning Project of Ministry of Housing and Urban-Rural Development, China (Grant No. 2010-K4-15).

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摘要： We investigated the effect of spin-orbit coupling on magnetoresistance in nonmagnetic organic semiconductors. A Lorentz-type magnetoresistance is obtained from spin-orbit coupling-dependent spin precession under the condition of a space-charge-limited current. The magnetoresistance depends on the initial spin orientation of the electron with respect to the hole in electron--hole pairs, and the increasing spin-orbit coupling slows down the change in magnetoresistance with magnetic field. The field dependence, the sign and the saturation value of the magnetoresistance are composite effects of recombination and dissociation rate constants of singlet and triplet electron--hole pairs. The simulated magnetoresistance shows good consistency with the experimental results.

关键词: organic magnetoresistance, spin-orbit coupling, recombination, spin precession

Abstract: We investigated the effect of spin-orbit coupling on magnetoresistance in nonmagnetic organic semiconductors. A Lorentz-type magnetoresistance is obtained from spin-orbit coupling-dependent spin precession under the condition of a space-charge-limited current. The magnetoresistance depends on the initial spin orientation of the electron with respect to the hole in electron--hole pairs, and the increasing spin-orbit coupling slows down the change in magnetoresistance with magnetic field. The field dependence, the sign and the saturation value of the magnetoresistance are composite effects of recombination and dissociation rate constants of singlet and triplet electron--hole pairs. The simulated magnetoresistance shows good consistency with the experimental results.

Key words: organic magnetoresistance, spin-orbit coupling, recombination, spin precession

中图分类号:  (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect)

  • 71.70.Ej
73.43.Qt (Magnetoresistance) 72.20.Jv (Charge carriers: generation, recombination, lifetime, and trapping) 72.80.Le (Polymers; organic compounds (including organic semiconductors))