摘要
从紧束缚模型出发,研究了聚合物分子中链间耦合对激子形成的影响.结果表明:光激发后耦合分子体系中形成的激子态有2种可能的分布:一种是激子在强耦合下仍主要局域在1条链中(称为"链间定域激子");另一种是激子在链间平均扩展(称为"链间扩展激子").通过计算链间耦合强度对这2种激子态的产生能和束缚能的影响,发现耦合体系中激发的电子-空穴更容易复合形成"链间定域激子".另外,通过分析链间耦合强度对激子束缚能的影响,表明聚合物分子之间的耦合不利于激子形成,因此固态薄膜的光致发光效率要低于其溶液状态.
Based on the framework of the tight binding approach, the formation of an exciton in inter - coupled polymer chains is studied. Both a localized exciton in one single chain and a spread exciton between chains are obtained. It is found that an excited electron - hole pair is more inclined to evolve into a localized exciton. By analyzing the effect of the interchain couplings on the exciton binding energy, it is shown that the photoluminescence efficiency of the polymer in a dilute solution state is higher than that in a solid state.
出处
《华南师范大学学报（自然科学版）》
CAS
2008年第4期53-58,共6页
Journal of South China Normal University(Natural Science Edition)
关键词
聚合物
激子
链间耦合
polymer
exciton
interchain coupling
