Department of Chemistry, Clemson University, Clemson, SC, 29634, USA.
Nat Commun. 2018 Oct 17;9(1):4314. doi: 10.1038/s41467-018-06846-2.
The performance of conjugated polymer devices is largely dictated by charge transport processes. However, it is difficult to obtain a clear relationship between conjugated polymer structures and charge transport properties, due to the complexity of the structure and the dispersive nature of charge transport in conjugated polymers. Here, we develop a method to map the energy landscape for charge transport in conjugated polymers based on simultaneous, correlated charge carrier tracking and single-particle fluorescence spectroscopy. In nanoparticles of the conjugated polymer poly[9,9-dioctylfluorenyl-2,7-diyl)-co-1,4-benzo-{2,1'-3}-thiadiazole)], two dominant chain conformations were observed, a blue-emitting phase (λ = 550 nm) and a red-emitting phase (λ = 595 nm). Hole polarons were trapped within the red phase, only occasionally escaping into the blue phase. Polaron hopping between the red-emitting traps was observed, with transition time ranging from tens of milliseconds to several seconds. These results provide unprecedented nanoscale detail about charge transport at the single carrier level.
共轭聚合物器件的性能在很大程度上取决于电荷输运过程。然而，由于共轭聚合物结构的复杂性和电荷输运的分散性，很难获得共轭聚合物结构与电荷输运性质之间的清晰关系。在这里，我们开发了一种基于同时相关的载流子追踪和单粒子荧光光谱学来绘制共轭聚合物中电荷输运的能量景观的方法。在共轭聚合物聚[9,9-二辛基芴-2,7-二基）-共-1,4-苯并{2,1'-3}-噻二唑]）的纳米颗粒中，观察到两种主要的链构象，一种是蓝色发射相（λ=550nm）和一种是红色发射相（λ=595nm）。空穴极化子被捕获在红色相中，只有偶尔逃入蓝色相中。观察到红色发射陷阱之间的极化子跳跃，跃迁时间从几十毫秒到几秒钟不等。这些结果提供了前所未有的关于单载流子水平电荷输运的纳米尺度细节。
