Ball Melissa L, Zhang Boyuan, Fu Tianren, Schattman Ayden M, Paley Daniel W, Ng Fay, Venkataraman Latha, Nuckolls Colin, Steigerwald Michael L
Department of Chemistry , Columbia University , New York , New York 10027 , USA . Email:
Department of Applied Physics and Applied Math , Columbia University , New York , New York 10027 , USA.
Chem Sci. 2019 Aug 28;10(40):9339-9344. doi: 10.1039/c9sc03144h. eCollection 2019 Oct 28.
Recent years have seen tremendous progress towards understanding the relation between the molecular structure and function of organic field effect transistors. The metrics for organic field effect transistors, which are characterized by mobility and the on/off ratio, are known to be enhanced when the intermolecular interaction is strong and the intramolecular reorganization energy is low. While these requirements are adequate when describing organic field effect transistors with simple and planar aromatic molecular components, they are insufficient for complex building blocks, which have the potential to localize a carrier on the molecule. Here, we show that intramolecular conductivity can play a role in controlling device characteristics of organic field effect transistors made with macrocycle building blocks. We use two isomeric macrocyclic semiconductors that consist of perylene diimides linked with bithiophenes and find that the -linked macrocycle has a higher mobility than the -based device. Through a combination of single molecule junction conductance measurements of the components of the macrocycles, control experiments with acyclic counterparts to the macrocycles, and analyses of each of the materials using spectroscopy, electrochemistry, and density functional theory, we attribute the difference in electron mobility of the OFETs created with the two isomers to the difference in intramolecular conductivity of the two macrocycles.
近年来，在理解有机场效应晶体管的分子结构与功能之间的关系方面取得了巨大进展。以迁移率和开/关比为特征的有机场效应晶体管的性能指标，已知在分子间相互作用强且分子内重组能低时会得到增强。虽然在描述具有简单平面芳香族分子成分的有机场效应晶体管时，这些条件是足够的，但对于有可能将载流子定位在分子上的复杂结构单元来说，它们是不够的。在这里，我们表明分子内导电性可以在控制由大环结构单元制成的有机场效应晶体管的器件特性中发挥作用。我们使用了两种由与联噻吩相连的苝二亚胺组成的异构大环半导体，发现与相连的大环相比，基于的器件具有更高的迁移率。通过对大环成分进行单分子结电导测量、用大环的无环对应物进行对照实验以及使用光谱学、电化学和密度泛函理论对每种材料进行分析，我们将用这两种异构体制造的有机场效应晶体管的电子迁移率差异归因于这两种大环分子内导电性的差异。
