链间耦合对聚合物分子中激子形成的影响  

EXCITON FORMATION WITH INTERCHAIN COUPLINGS IN ORGANIC POLYMERS

作　　者：官文栎[1] 于元勋[1] 

机构地区：[1]山东教育学院物理科学与技术系,山东济南250013

出　　处：《华南师范大学学报（自然科学版）》2008年第4期53-58,共6页Journal of South China Normal University(Natural Science Edition)

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.

关 键 词：聚合物 激子 链间耦合 

分 类 号：O469[理学—凝聚态物理]