Parameter free calculation of the subgap density of states in poly(3-hexylthiophene).
Parameter free calculation of the subgap density of states in poly(3-hexylthiophene).
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DOI：
10.1039/c4fd00153b
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发表时间：
2014-12
影响因子：
3.4
通讯作者：
J. Frost;J. Kirkpatrick;T. Kirchartz;J. Nelson
中科院分区：
文献类型：
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作者：
J. Frost;J. Kirkpatrick;T. Kirchartz;J. Nelson
利用原子分子动力学模拟聚合物薄膜结构和紧束缚电子能级计算相结合的方法，研究了共轭聚合物中链内和链间相互作用对亚能隙态密度的影响.对于聚-3-己基噻吩的无序组装，我们发现空穴态密度的尾部近似为指数，特征能量为37 meV，这与实验值相似。这种状态的尾部主要来自相邻单体之间的电子耦合的变化，并且仅受链间耦合的轻微影响。因此，相邻单体之间的扭转无序的知识足以估计聚合物的态密度。然而，链内扭转无序主要由链的堆积而不是扭转势决定。我们提出的组合方法作为一种工具，设计更高的流动性共轭聚合物。
We investigate the influence of intra-chain and inter-chain interactions on the sub-gap density of states in a conjugated polymer using a combination of atomistic molecular dynamics simulation of polymer film structure and tight-binding calculation of electronic energy levels. For disordered assemblies of poly-3-hexylthiophene we find that the tail of the density of hole states is approximately exponential with a characteristic energy of 37 meV, which is similar to experimental values. This tail of states arises mainly from variations in the electronic coupling between neighbouring monomers, and is only slightly influenced by interchain coupling. Thus, knowledge of the disorder in torsion between neighbouring monomers is sufficient to estimate the density of states for the polymer. However, the intrachain torsional disorder is determined largely by the packing of the chains rather than the torsional potential alone. We propose the combination of methods as a tool to design higher mobility conjugated polymers.