链间耦合对极化子非弹性散射性质的影响

The effect of interchain coupling on inelastic scattering of oppositely charged polarons

基于一维紧束缚的Su-Schreiffer-Heeger模型,采用非绝热动力学方法,研究了链间耦合对聚合物中极化子对非弹性散射性质的影响:激子的产生依赖于链间耦合,随着耦合强度的增加,正负极化子对的电子波函数交叠增强,利于提高激子的产率;当耦合区域是极化子的宽度时,正负极化子对波函数的耦合最充分、耦合最强,电荷跃迁更容易,激子产率最大.

Within an one-dimensional tight-binding Su-Schreiffer-Heeger model,we investigate the effect of interchain coupling on inelastic scattering of oppositely charged polarons in conjugated polymer by using a nonadiabatic evolution method.It is found that the yield of the neutral exciton depends sensitively on the interchain coupling.The yield of the neutral exciton increases with the enhancement of overlapping which can make the wave functions of oppositely charged polarons more largely overlapped.The formation yield of excitons also increases with the number of overlapping sites increasing to its maximum value,where the length of overlapping sites is almost of the same order of magnitude as the width of the polaron,the reason is that the number of overlapping sites can affect the overlap of oppositely charged polaron wave functions.In turn,the charge transfer between them depends on the overlap of their wave functions.Therefore,when the size of overlapping sites is almost of the same order of magnitude as the width of the polaron,their wave functions have a largest overlap,thereby making charge transfer more easily.So the yield of excitons has the largest value.