Nearly Isotropic Conjugated Polymer Aggregates with Efficient Local Exciton Diffusion
Nearly Isotropic Conjugated Polymer Aggregates with Efficient Local Exciton Diffusion
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DOI：
10.1021/acs.jpcc.9b08075
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
Youngah Kwon;L. Kaufman
中科院分区：
文献类型：
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作者：
Youngah Kwon;L. Kaufman
为了弥合有机半导体的单分子和本体薄膜研究之间的差距，并理解分子结构对跨尺度的物理性质的影响，我们通过良好控制的溶剂蒸气溶胀惰性聚合物基质制备并表征了包含几个到一千多个单链的聚集体，所述惰性聚合物基质包含共轭聚合物聚[2-甲氧基-5-（2-甲氧基-5-甲氧基苯基）-5-（2-甲氧基苯基）（2-乙基己氧基）-1，4-亚苯基亚乙烯基]（MEH-PPV）。单链最初固定在构象与链间接触很少，这可以支持激子功能的单分子水平。我们表明，通过溶剂溶胀和模板上这样的分子制备的聚集体在很大程度上各向同性聚集体的结果。聚合物的极化各向异性，光致发光瞬态衰减，和光致发光光谱作为聚集体尺寸的函数的分析表明，在这些聚集体激子扩散局部增强初始聚集后，但没有达到扩展的长度…
To bridge the gap between single-molecule and bulk thin film studies of organic semiconductors and understand the influence of molecular structure on photophysical properties across scales, we prepared and characterized aggregates containing a few to more than a thousand single chains via well-controlled solvent vapor swelling of an inert polymeric matrix containing the conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). The single chains were initially immobilized in conformations with few interchain contacts, which can support exciton funneling on the single-molecule level. We show that aggregates prepared via solvent swelling and templated on such molecules result in largely isotropic aggregates. Analysis of aggregate polarization anisotropy, photoluminescence transient decay, and photoluminescence spectra as a function of aggregate size suggests that in these aggregates exciton diffusion is locally enhanced upon initial aggregation but does not reach extended length...