共轭高聚物双分子结构中激子电致解离的动力学研究

Dynamics study of electric field induced exciton dissociation in conjugated polymer bimolecular structure

通过绝热动力学方法,研究了共轭高聚物双分子结构中激子对外加电场的响应.当外电场强度超过某个临界值时,激子会被解离成一对自由的电子与空穴.对于双分子结构中的激子,其临界解离电场除了受电子与电子相互作用以及电声相互作用影响之外,还受分子间相互作用的影响.由动力学演化的计算得到,激子临界解离电场强度随分子间相互作用强度的增大而呈非线性降低;随电子与电子相互作用强度的增大呈非线性减小的变化;但是,随电声耦合强度的增大却呈现出线性增大的变化.

By virtue of adiabatic dynamics method,the response of excitons upon an external electric field is studied in a conjugated polymer bimolecular structure.As the electric field strength is over the critical value,the exciton is dissociated into a couple of free electron and hole.For the excitons in a bimolecular structure,the crit⁃ical dissociation field is affected by the interaction of the molecules,as well as by the electron-electron interac⁃tion and the electron-phonon interaction.Due to the dynamical evolution calculations,the critical electric field strength of exciton dissociation decreases nonlinearly as the interchain interaction increases.The critical dissocia⁃tion field strength also decreases nonlinearly with the increase of electron-electron interaction strength.Howev⁃er,the critical dissociation field strength increases linearly as electron-phonon interaction strength increases.