共轭高分子中激子演化过程的非绝热动力学研究

有机共轭高分子受光激发或被电荷掺杂后可能会产生各种激发状态的激子,激子的演化过程对有机发光光谱有着至关重要的影响.通过非绝热动力学演化的方法模拟了受光激发后有机高分子中激子驰豫的动力学过程,结果表明高激发态激子不稳定,由于电声耦合作用,高激发态激子会持续向低激发态激子演化,同时,低激发态激子的复合发光会发生红移.稳定的激子复合发光光谱中,基态激子发光强度最大,可高达70-80%;第一激发态激子及其它激发态激子发光强度的总和不超过20%.

Nonadiabatic dynamics study upon exciton formation in a conjugated polymer chainNonadiabatic dynamics study upon exciton relaxation process in a conjugated polymer chain

In organic conjugated polymers, charge injection or photo-excitation can result in excitons of various excited state. The relaxation of excited state excitons plays an important roll on the luminescence spectrum. A nonadiabatic dynamics evolution approach is used to study the relaxation process of the excited state excitons in conjugated polymer chains. It shows that the high excited state excitons are unstable. They will keep relaxing toward low excited state due to electron-phonon coupling. In addition, a red shift occurs in the spectrum of low excited state excitons. The intensity of the combination luminescence of the ground state exciton can reach up to 80%. The intensity of the combination luminescence of the 1st excited state exciton and other low excited state excitons is less than 20%.