Dynamics of charge injection into an open conjugated polymer: A nonadiabatic approach
Dynamics of charge injection into an open conjugated polymer: A nonadiabatic approach
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电荷注入开放共轭聚合物的动力学：非绝热方法
DOI：
10.1103/physrevb.73.195401
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发表时间：
2006-05
影响因子：
3.7
通讯作者：
Ren, Jun-Feng
中科院分区：
文献类型：
--
作者：
Fu, Ji-Yong;Liu, Xiao-Jing;Xie, Shi-Jie;Liu, De-Sheng;Ren, Jun-Feng
在非绝热方法的框架中研究了与金属电极接触的开放共轭聚合物链的电荷注入动态过程。研究发现，由于共轭聚合物中强烈的电子-晶格相互作用，注入的电荷形成波包。波包可以包含最多两个电子单元的任意数量的电荷，这取决于注入条件。由于系统在当前模型中是自旋简并的，因此波包没有自旋。伴随波包的间隙中会出现离散的能级，这导致金属电极和聚合物之间电荷注入和排出的电位不对称。这种不对称性可以用来解释有机器件中的电滞现象。发现存在上临界场或形成场，超过该上临界场或形成场，注入的电荷不能形成波包。在强驱动电场下，还发现波包会解离成扩展态。研究了离解场对波包所含电荷量的依赖性。
The dynamic process of charge injection is investigated for an open conjugated polymer chain in contact with a metal electrode in the framework of a nonadiabatic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interactions in the conjugated polymer. A wave packet may contain any quantity of charges up to two electronic units, which depends upon the injection condition. As the system is spin degenerate within the present model, a wave packet has no spin. Discrete energy levels will appear in the gap accompanying the wave packet, which results in potential asymmetry of the charge injection and ejection between the metal electrode and the polymer. The asymmetry can be used to explain the electrical hysteresis in organic devices. It is found that there exists an upper critical field or forming field, beyond which the injected charges could not form a wave packet. Under a strong driving electric field, it is also found that a wave packet will dissociate into an extended state. The dependence of the dissociating field on the charge quantity a wave packet contains is studied.