Put Your Backbone into It: Excited-State Structural Relaxation of PffBT4T-2DT Conducting Polymer in Solution
Put Your Backbone into It: Excited-State Structural Relaxation of PffBT4T-2DT Conducting Polymer in Solution
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DOI：
10.1021/acs.jpcc.8b01356
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发表时间：
2018-03-29
影响因子：
3.7
通讯作者：
Moule, Adam J.
中科院分区：
文献类型：
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作者：
Dantanarayana, Varuni;Fuzell, Jack;Moule, Adam J.
有机半导体中的构象和能量无序由于结构缺陷而降低了电荷和激子传输，从而降低了器件如有机光致发光器件和有机发光二极管的效率。主要的结构不均匀性是因为聚合物主链的扭曲，即使在大部分是结晶的聚合物中也会发生这种扭曲。在这里，我们探索聚合物主链扭曲和激子离域的瞬态吸收光谱和密度泛函理论计算的装置之间的关系。我们研究了PffBT 4 T-2DT聚合物，该聚合物与非富勒烯受体相比，表现出比目前破纪录的PCE 11聚合物更高的器件效率。我们确定的驱动力，由激发引起的聚合物链的平面化。该方法具有普遍适用性，并且对激发态非平面结构的惩罚比基态更高。这项研究突出了共轭聚合物的形态和电子的变化所带来的激发。
Conformational and energetic disorder in organic semiconductors reduces charge and exciton transport because of the structural defects, thus reducing the efficiency in devices such as organic photovoltaics and organic light-emitting diodes. The main structural heterogeneity is because of the twisting of the polymer backbone that occurs even in polymers that are mostly crystalline. Here, we explore the relationship between polymer backbone twisting and exciton delocalization by means of transient absorption spectroscopy and density functional theory calculations. We study the PffBT4T-2DT polymer which has exhibited even higher device efficiency with nonfullerene acceptors than the current record breaking PCE11 polymer. We determine the driving force for planarization of a polymer chain caused by excitation. The methodology is generally applicable and demonstrates a higher penalty for nonplanar structures in the excited state than in the ground state. This study highlights the morphological and electronic changes in conjugated polymers that are brought about by excitation.