齐分子吡咯中极化子和双极化子及其稳定性  

The stability of polaron and bipolaron in oligopyrrole

作　　者：李冬梅[1] 张大成[1] 宋骏[1] 刘德胜[1] 解士杰[1] 

机构地区：[1]山东大学物理与微电子学院

出　　处：《山东大学学报（理学版）》2004年第3期64-68,71,共6页Journal of Shandong University(Natural Science)

基　　金：国家自然科学基金重大研究计划项目(90103031);国家自然科学基金资助项目(10074040);山东省自然科学基金资助项目(Y2001A05)

摘　　要：采用半经验Austin Model 1(AM1)方法,计算了齐分子吡咯聚合物(PPy)的中性态和带电态的几何结构性质.与中性态相比,带电态下其分子结构表现在C-C键长发生显著改变,单电荷掺杂导致极化子元激发;当掺杂的双电荷随机放置时,出现了两种情况:一种情况下产生双极化子,另一种情况下会产生两个分立的极化子.通过控制链的长度,可实现极化子与双极化子之间的相变,从而揭示出在有机半导体材料中实现自旋极化输运的可能性.The results of Austin Model 1 (AM1) geometry optimization calculations are presented to determine the neutral and charged geometry properties of oligopyrrole. Comparing with the neutral states, the changes of the bond lengths of the charged states are very evident. The single oxidized state is corresponding to a polaron and the doubly oxidized state to a bipolaron. But in the case of the lengths n≥4m (m = 4) , the doubly oxidized state is corresponding to two separate polarons. It was found that a transition between bipolarons and polarons would be possible by adjusting the lengths of the chains. The investigation is helpful to understand spin-polarized transport in organic semiconductor materials.

关 键 词：齐聚物 元激发 极化子 双极化子 

分 类 号：O469[理学—凝聚态物理]