Improving the Electrical Connection of n-Type Conjugated Polymers through Fluorine-Induced Robust Aggregation
Improving the Electrical Connection of n-Type Conjugated Polymers through Fluorine-Induced Robust Aggregation
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DOI：
10.1021/acs.chemmater.9b01469
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发表时间：
2019-07-09
影响因子：
8.6
通讯作者：
Park, Taiho
中科院分区：
文献类型：
--
作者：
Kim, Minjun;Park, Won-Tae;Park, Taiho
以联噻吩二亚胺(NDI)为基元的联苯二亚胺(NDI)共轭聚合物可以通过NDI驱动的自组装形成较大的晶区，作为n型材料广泛应用于有机电子器件中。然而，改善这些半导体聚合物中的电子传输一直是一个重大的挑战，主要是因为晶体结构域之间的电性连接很差。形成具有短程有序和混合取向的小区域的互联网络是提高聚合物材料电子迁移率(Mu(E))的有效途径。本研究论证了使用含氟TVT(FTVT)单元组成的基于NDI的聚合物的这种方法的可行性。FTVT单元增强了聚合物链之间的分子间相互作用，导致了强劲的聚集。这种聚集被发现抑制了NDI驱动的自组装，导致了相互连接的小晶域，具有短程有序性和良好的高温热稳定性。这种微结构通过降低能量无序以及在不同温度下一致的电连通性，为晶体管器件提供了改进的Mu(E)。
Naphthalene diimide (NDI)-based conjugated polymers with bithiophene or dithienylethene (TVT) units can form large crystal domains through NDI-driven self-assembly and are widely used in organic electronic devices as n-type materials. However, improving electron transport in these semiconducting polymers has been a significant challenge mainly due to poor electrical connections between the crystal domains. Formation of an interconnected network of small domains with short-range ordering and mixed orientations could be an effective way of increasing the electron mobility (mu(e)) of polymeric materials. The present study demonstrates the feasibility of this approach using an NDI-based polymer composed of fluorinated TVT (FTVT) units. The FTVT unit enhances intermolecular interactions between the polymer chains, leading to robust aggregation. This aggregation was found to suppress NDI-driven self-assembly, resulting in interconnected small crystal domains with short-range ordering and good thermal stability at elevated temperatures. This microstructure provided transistor devices with improved mu(e) by lowering energetic disorder as well as consistent electrical connectivity at different annealing temperatures.