电致发光聚合物在外电场中行为的动力学研究

用电子－晶格耦合的紧束缚模型和求介实时牛顿动力学方程的方法研究了具有额外电子和空穴的电致发光高分子在外电场中的行为。发现外电场注入的额外电子和空穴使电致发光高分子晶格弛豫，形成双极化子激子；并存在一个临界电场，当外电场大于或者等于临界电场时，双极化子激子解离成正、负极化子，导致发光猝灭．该结果与电致发光高分子的光荧光被强电场猝灭的实验现象一致．这个一致性反映了双极化子激子是电致发光高分子中的一种发光实体，说明了电致发光高分子在强电场下光荧光猝灭的物理原因是在强电场作用下电致发光高分子中的双极化子激子被解离成正、负极化子

DYNAMICAL STUDY ON THE BEHAVIOR OF ELECTROLUMINESCENT POLYMERS UNDER APPLIED ELECTRIC-FIELDS

The behaviors of the electroluminescent polymers under applied electric fields were studied by using the tight binding model of electron lattice coupling and solving the real tmie Newton dynamical equation. It was discovered that (1) the extra electron and hole injected by the applied electric field make the lattice relaxation, and bipolaron excitons are formed. (2) there exists a critical electric field. When an applied field is equal to or larger than the critical field, the bipolaron exciton will be dissociated into positive and negative polarons, leading to photoluminescence quenching. The result is consistent with the relevant experiments, and it also implies that the bipolaron exciton is a kind of luminous species in polymers.