Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping, Sweden.
J Chem Phys. 2011 Aug 21;135(7):074902. doi: 10.1063/1.3624730.
By using the Su-Schrieffer-Heeger model modified to include electron-electron interactions, the Brazovskii-Kirova symmetry breaking term and an external electric field, we investigate the scattering process between a negative and a positive bipolaron in a system composed of two coupled polymer chains. Our results show that the Coulomb interactions do not favor the bipolaron recombination. In the region of weak Coulomb interactions, the two bipolarons recombine into a localized excited state, while in the region of strong Coulomb interactions they can not recombine. Our calculations show that there are mainly four channels for the bipolaron recombination reaction: (1) forming a biexciton, (2) forming an excited negative polaron and a free hole, (3) forming an excited positive polaron and a free electron, (4) forming an exciton, a free electron, and a free hole. The yields for the four channels are also calculated.
利用包含电子-电子相互作用、Brazovskii-Kirova 对称破缺项和外电场的修正 Su-Schrieffer-Heeger 模型，我们研究了由两个耦合聚合物链组成的系统中一个负双极化子和一个正双极化子之间的散射过程。我们的结果表明，库仑相互作用不利于双极化子复合。在库仑相互作用较弱的区域，两个双极化子复合成一个局域激发态，而在库仑相互作用较强的区域，它们不能复合。我们的计算表明，双极化子复合反应主要有四个通道：（1）形成双激子，（2）形成一个激发的负极化子和一个自由空穴，（3）形成一个激发的正极化子和一个自由电子，（4）形成激子、一个自由电子和一个自由空穴。我们还计算了这四个通道的产率。
