Abstract

We present theoretical studies to explore interchain polaron pair (PP) formation in conjugated polymers. Based on the Pariser-Parr-Pople (PPP) Hamiltonian combined with the configuration interaction singles (CIS), we perform excited-state geometry optimization on a poly-p-phenylenevinylene (PPV) dimer, and identify interchain PPs in this system by analyzing the real-space distributions of electron and hole in different excited states. We find that interchain PP states can not form in highly symmetric cofacial PPV-dimer, but can form in this PPV-dimer when applying an external electric field, rotating one of two chains, or doping an impurity. Considering that highly symmetric systems are hardly present in real polymer films, PPs should commonly exist as high-lying excited states of real polymer systems.

Graphical abstract

中文翻译：

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探索纯共轭聚合物中链间极化子对的形成

摘要

我们目前进行理论研究，以探索共轭聚合物中链间极化子对（PP）的形成。基于Pariser-Parr-Pople（PPP）哈密顿量和配置相互作用单（CIS），我们对聚对苯撑乙烯撑（PPV）二聚体进行了激发态几何优化，并通过分析确定了该系统中的链间PP电子和空穴在不同激发态下的真实空间分布。我们发现链间PP状态不能在高度对称的PPV二聚体中形成，但是在施加外部电场，旋转两条链中的一条或掺杂杂质时可以在PPV二聚体中形成。考虑到在实际的聚合物薄膜中几乎不存在高度对称的系统，因此PP通常应作为实际的聚合物系统的高激发态存在。

图形概要