Selenium-Containing Fused Bicyclic Heterocycle Diselenolodiselenole: Field Effect Transistor Study and Structure–Property Relationship

The
first application of the diselenolodiselenole (C4Se4) heterocycle as an active organic field effect transistor
materials is demonstrated here. C4Se4 derivatives
(2a–2d) were obtained by using a
newly developed straightforward diselenocyclization protocol, which
includes the reaction of diynes with selenium powder at elevated temperature.
C4Se4 derivatives exhibit strong donor characteristics
and planar structure (except 2d). The atomic force microscopic
analysis and thin-film X-ray diffraction pattern of compounds 2a–2d indicated the formation of distinct
crystalline films that contain large domains. A scanning electron
microscopy study of compound 2b showed development of
symmetrical grains with an average diameter of 150 nm. Interestingly, 2b exhibited superior hole mobility, approaching 0.027 cm2 V–1 s–1 with a transconductance
of 9.2 μS. This study correlate the effect of π-stacking,
Se···Se intermolecular interaction, and planarity with
the charge transport properties and performance in the field effect
transistor devices. We have shown that the planarity in C4Se4 derivatives was achieved by varying the end groups
attached to the C4Se4 core. In turn, optoelectronic
properties can also be tuned for all these derivatives by end-group
variation.

本文首次报道了二硒醇并二硒杂环（diselenolodiselenole, C4Se4）作为活性有机场效应晶体管材料的应用。通过一种新开发的简便二硒环化合成策略——二炔类化合物与硒粉在高温下的反应，可制备得到C4Se4衍生物（2a–2d）。该类C4Se4衍生物除2d外，均具备较强的给电子特性与平面共轭结构。对化合物2a–2d开展的原子力显微镜（atomic force microscopy, AFM）分析与薄膜X射线衍射测试结果表明，其可形成具有大尺寸畴区的规整结晶薄膜。对化合物2b的扫描电子显微镜（scanning electron microscopy, SEM）研究显示，其表面可形成平均粒径约150 nm的对称晶粒。值得注意的是，化合物2b展现出优异的空穴迁移率，最高可达0.027 cm²·V⁻¹·s⁻¹，跨导为9.2 μS。本研究探讨了π堆叠、Se···Se分子间相互作用以及平面性对有机场效应晶体管器件电荷传输性能与器件整体性能的影响。研究表明，通过改变连接于C4Se4母核的端基，可调控该类衍生物的平面性；相应地，通过端基修饰还可调节该类衍生物的光电性能。