Nat Mater. 2011 Oct 9;10(12):942-6. doi: 10.1038/nmat3127.
Applications of conjugated polymers (CP) in organic electronic devices such as light-emitting diodes and solar cells depend critically on the nature of electronic energy transport in these materials. Single-molecule spectroscopy has revealed their fundamental properties with molecular detail, and recent reports suggest that energy transport in single CP chains can extend over extraordinarily long distances of up to 75 nm. An important question arises as to whether these characteristics are sustained when CP chains agglomerate into a neat solid. Here, we demonstrate that the electronic energy transport in aggregates composed of tens of polymer chains takes place on a similar distance scale as that in single chains. A recently developed molecular-level understanding of solvent vapour annealing has allowed us to develop a technique to control the CP agglomeration process. Aggregates with volumes of at least 45,000 nm(3) (molecular weight ≈ 21 MDa) maintain a highly ordered morphology and show pronounced fluorescence blinking behaviour, indicative of substantially long-range energy transport. Our findings provide a new lens through which the ordering of single CP chains and the evolution of their morphological and optoelectronic properties can be observed, which will ultimately enable the rational design of improved CP-based devices.
共轭聚合物（CP）在有机电子器件（如发光二极管和太阳能电池）中的应用，关键取决于这些材料中电子能量传输的性质。单分子光谱学以分子细节揭示了它们的基本性质，最近的报告表明，在单 CP 链中能量传输可以延伸到长达 75nm 的非常远距离。一个重要的问题是，当 CP 链聚集到纯净的固体中时，这些特性是否能够持续。在这里，我们证明了由数十个聚合物链组成的聚集体中的电子能量传输发生在与单链相似的距离范围内。最近对溶剂蒸汽退火的分子水平理解使我们能够开发一种控制 CP 聚集过程的技术。具有至少 45000nm3（分子量≈21MDa）体积的聚集体保持高度有序的形态，并表现出明显的荧光闪烁行为，表明存在显著的长程能量传输。我们的发现提供了一个新的视角，可以观察单 CP 链的有序化以及它们的形态和光电性质的演变，这将最终能够实现基于 CP 的改进器件的合理设计。
