Department of Molecular Physics, Faculty of Chemistry, Lodz University of Technology , Zeromskiego 116, 90-924 Lodz, Poland.
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg , 69120 Heidelberg, Germany.
ACS Appl Mater Interfaces. 2017 Jun 21;9(24):20696-20703. doi: 10.1021/acsami.7b03399. Epub 2017 Jun 12.
Ambipolar organic field-effect transistors (OFETs) based on heterojunction active films still suffer from an imbalance in the transport of electrons and holes. This problem is related to an uncontrolled phase separation between the donor and acceptor organic semiconductors in the thin films. In this work, we have developed a concept to improve the phase separation in heterojunction transistors to enhance their ambipolar performance. This concept is based on preaggregation of the donor polymer, in this case poly(3-hexylthiophene) (P3HT), before solution mixing with the small-molecular-weight acceptor, phenyl-C61-butyric acid methyl ester (PCBM). The resulting heterojunction transistor morphology consists of self-assembled P3HT fibers embedded in a PCBM matrix, ensuring balanced mobilities reaching 0.01 cm/V s for both holes and electrons. These are the highest mobility values reported so far for ambipolar OFETs based on P3HT/PCBM blends. Preaggregation of the conjugated polymer before fabricating binary blends can be regarded as a general concept for a wider range of semiconducting systems applicable in organic electronic devices.
基于异质结活性薄膜的双极有机场效应晶体管（OFET）仍然存在电子和空穴输运不平衡的问题。这个问题与薄膜中给体和受体有机半导体之间不受控制的相分离有关。在这项工作中，我们提出了一个概念，以改善异质结晶体管中的相分离，从而提高其双极性性能。该概念基于在与小分子受体，即苯基-C61-丁酸甲酯（PCBM）混合溶液之前对给体聚合物（在此情况下为聚（3-己基噻吩）（P3HT））进行预聚集。所得异质结晶体管形态由自组装的 P3HT 纤维嵌入 PCBM 基质组成，确保空穴和电子的迁移率均达到 0.01 cm/V s。这是迄今为止报道的基于 P3HT/PCBM 共混物的双极 OFET 的最高迁移率值。在制造二元共混物之前对共轭聚合物进行预聚集可以被视为适用于有机电子器件的更广泛半导体系统的通用概念。
