Dynamical Study of Impurity Effects on Bipolaron鈥揃ipolaron and Bipolaron鈥揚olaron Scattering in Conjugated Polymers

详细信息    查看全文

• 作者：Luiz Antonio Ribeiro ; Wiliam Ferreira da Cunha ; Pedro Henrique de Oliveira Neto ; Ricardo Gargano ; Geraldo Magela e Silva
• 刊名：Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：October 3, 2013
• 年：2013
• 卷：117
• 期：39
• 页码：11801-11811
• 全文大小：681K
• 年卷期：v.117,no.39(October 3, 2013)
• ISSN：1520-5207

文摘

Combining the one-dimensional tight-binding Su鈥揝chrieffer鈥揌eeger (SSH) model and the extended Hubbard model (EHM), the scattering of two oppositely charged bipolarons and a bipolaron鈥損olaron pair is investigated under the influence of impurity effects using a nonadiabatic evolution method. These novel results for bipolarons show that the oppositely charged quasi-particles scatter into a mixed state composed of bipolarons and excitons. The excitation yield depends sensitively on the strength of the applied electric field. In the presence of an impurity, the critical electric field regime for formation of a state composed by bipolarons and excitons is increased. Additionally, we were able to obtain critical values of electric fields that played the role of drastically modifying the system dynamics. These facts suggest that the scattering between bipolarons and a bipolaron鈥損olaron pair in the presence of impurities is crucial for the understanding of electroluminescence in optoelectronics devices, such as polymer light emitting diodes.