Effect of disorder on exciton dissociation in conjugated polymers  

作　　者：冯誉雯 赵晖 陈宇光 鄢永红 

机构地区：[1]Department of Physics Tongji University [2]Department of Physics Shaoxing University

出　　处：《Chinese Physics B》2017年第10期417-422,共6页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11474218 and 11575116)

摘　　要：By using a multi-configurational time-dependent Hartree-Fock （MCTDHF） method for the time-dependent Schrrdinger equation and a Newtonian equation of motion for lattice, we investigate the disorder effects on the dissociation process of excitons in conjugated polymer chains. The simulations are performed within the framework of an extended version of the Su-Schrieffer-Heeger model modified to include on-site disorder, off-diagonal, electron-electron interaction, and an external electric field. Our results show that Coulomb correlation effects play an important role in determining the exciton dissociation process. The electric field required to dissociate an exciton can practically impossibly occur in a pure polymer chain, especially in the case of triplet exciton. However, when the on-site disorder effects are taken into account, this leads to a reduction in mean dissociation electric fields. As the disorder strength increases, the dissociation field decreases effectively. On the contrary, the effects of off-diagonal disorder are negative in most cases. Moreover, the dependence of exciton dissociation on the conjugated length is also discussed.By using a multi-configurational time-dependent Hartree-Fock （MCTDHF） method for the time-dependent Schrrdinger equation and a Newtonian equation of motion for lattice, we investigate the disorder effects on the dissociation process of excitons in conjugated polymer chains. The simulations are performed within the framework of an extended version of the Su-Schrieffer-Heeger model modified to include on-site disorder, off-diagonal, electron-electron interaction, and an external electric field. Our results show that Coulomb correlation effects play an important role in determining the exciton dissociation process. The electric field required to dissociate an exciton can practically impossibly occur in a pure polymer chain, especially in the case of triplet exciton. However, when the on-site disorder effects are taken into account, this leads to a reduction in mean dissociation electric fields. As the disorder strength increases, the dissociation field decreases effectively. On the contrary, the effects of off-diagonal disorder are negative in most cases. Moreover, the dependence of exciton dissociation on the conjugated length is also discussed.

关 键 词：POLYMER EXCITON electron-electron correlation dynamical evolution 

分 类 号：O631[理学—高分子化学]