中国物理B ›› 2013, Vol. 22 ›› Issue (6): 67103-067103.doi: 10.1088/1674-1056/22/6/067103

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

The effect of interface hopping on inelastic scattering of oppositely charged polarons in polymers

邸冰a, 王亚东a b, 张亚琳a, 安忠a   

  1. a College of Physics and Hebei Advanced Thin Films Laboratory, Hebei Normal University, Shijiazhuang 050024, China;
    b Zhangjiakou Vocational and Technical College, Zhangjiakou 075051, China
  • 收稿日期:2012-10-31 修回日期:2012-11-28 出版日期:2013-05-01 发布日期:2013-05-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 11074064), the Key Project of the Ministry of Education of China (Grant No. 210021), and the Natural Science Fund of Hebei Province of China (Grant No. A2010000357).

The effect of interface hopping on inelastic scattering of oppositely charged polarons in polymers

Di Bing (邸冰)a, Wang Ya-Dong (王亚东)a b, Zhang Ya-Lin (张亚琳)a, An Zhong (安忠)a   

  1. a College of Physics and Hebei Advanced Thin Films Laboratory, Hebei Normal University, Shijiazhuang 050024, China;
    b Zhangjiakou Vocational and Technical College, Zhangjiakou 075051, China
  • Received:2012-10-31 Revised:2012-11-28 Online:2013-05-01 Published:2013-05-01
  • Contact: An Zhong E-mail:zan@hebtu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 11074064), the Key Project of the Ministry of Education of China (Grant No. 210021), and the Natural Science Fund of Hebei Province of China (Grant No. A2010000357).

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摘要： The inelastic scattering of oppositely charge polarons in polymer heterojunctions is believed to be fundamental importance for the light-emitting and transport properties of conjugated polymers. Based on the tight-binding SSH model, and by using a nonadiabatic molecular dynamic method, we investigate the effects of interface hopping on inelastic scattering of oppositely charged polarons in a polymer heterojunction. It is found that the scattering processes of the charge and lattice defect depend sensitively on the hopping integrals at the polymer/polymer interface when the interface potential barrier and applied electric field strength are constant. In particular, at an intermediate electric field, when the interface hopping integral of the polymer/polymer heterojunction material is increased beyond a critical value, two polarons can combine to become a lattice deformation in one of the two polymer chains, with the electron and the hole bound together, i.e., a self-trapped polaron-exciton. The yield of excitons then increases to a peak value. These results show that interface hopping is of fundamental importance and facilitates the formation of polaron-excitons.

关键词: polarons, electron-phonon interactions, exciton, polymers

Abstract: The inelastic scattering of oppositely charge polarons in polymer heterojunctions is believed to be fundamental importance for the light-emitting and transport properties of conjugated polymers. Based on the tight-binding SSH model, and by using a nonadiabatic molecular dynamic method, we investigate the effects of interface hopping on inelastic scattering of oppositely charged polarons in a polymer heterojunction. It is found that the scattering processes of the charge and lattice defect depend sensitively on the hopping integrals at the polymer/polymer interface when the interface potential barrier and applied electric field strength are constant. In particular, at an intermediate electric field, when the interface hopping integral of the polymer/polymer heterojunction material is increased beyond a critical value, two polarons can combine to become a lattice deformation in one of the two polymer chains, with the electron and the hole bound together, i.e., a self-trapped polaron-exciton. The yield of excitons then increases to a peak value. These results show that interface hopping is of fundamental importance and facilitates the formation of polaron-excitons.

Key words: polarons, electron-phonon interactions, exciton, polymers

中图分类号:  (Polarons and electron-phonon interactions)

  • 71.38.-k
72.20.Jv (Charge carriers: generation, recombination, lifetime, and trapping) 71.35.Aa (Frenkel excitons and self-trapped excitons) 72.80.Le (Polymers; organic compounds (including organic semiconductors))