Determining the Exciton Diffusion Length in a Polyfluorene from Ultrafast Fluorescence Measurements of Polymer/Fullerene Blend Films
Determining the Exciton Diffusion Length in a Polyfluorene from Ultrafast Fluorescence Measurements of Polymer/Fullerene Blend Films
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DOI：
10.1021/jp404985q
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发表时间：
2013-10-03
影响因子：
3.7
通讯作者：
Haque, S. A.
中科院分区：
文献类型：
--
作者：
Bruno, A.;Reynolds, L. X.;Haque, S. A.
研究了[9，9-dioctylfluorene-co-N-(4-butylPhenyl)-diphenylamine]与不同浓度的三种不同类型的受体：[6，6]-苯基-C61-丁酸甲酯及其多加成类似物双-苯基-C61-丁酸甲酯和三种不同类型的受体组成的体系中的发射猝灭。我们发现，对于给定的富勒烯浓度，发射猝灭程度随着PCBM加成物数目的增加而降低，而透射电子显微镜观察到的微结构则变得更加粗糙。根据富勒烯在聚合物中的混溶程度和不同的激发解离速率可能存在的差异，这些观察结果是合理的。我们还从超快荧光衰变测量中提取了激子在TFB中的扩散长度为9.0+/-2 nm。这一结果已经通过独立的测量得到了证实。
Emission quenching is studied in systems composed of [9,9-dioctylfluorene-co-N-(4-butylPhenyl)-diphenylamine] (TFB) and various concentrations of three different types of acceptors: [6,6]-phenyl-C61 butyric acid methyl ester (mono-PCBM) and its multiadduct analogues bis-PCBM and tris-PCBM. We find that the degree of emission quenching for a given fullerene concentration decreases as the PCBM adduct number increases, while the microstructure, as observed with transmission electron microscopy, becomes more coarse. These observations are rationalized in terms of possible differences in the miscibility of fullerenes in the polymer and different excitation dissociation rates. We also extract a value for the exciton diffusion length in TFB of 9.0 +/- 2 nm from ultrafast fluorescence decay measurements. The results have been confirmed with independent measurements.