Controlled Self-Assembly And Field-Effect Transistors Of Trichalcogenasumanene

The discovery of fullerene has attracted widespread attention due to its unique structure and excellent physicochemical properties.C_5V symmetrical fullerenes（corannulene）and C_3V symmetries（sumanene）are two representative types of curvedπ-conjugated molecules.Due to the curved conjugation backbones,such molecules are interesting in areas such as self-assembly and organic optoelectronics.Therefore,it is important to explore the assembly and optoelectronic property of the molecules.In this thesis,the assembly characteristics and optoelectronic properties of sumanene derivatives are studied.High-performance field-effect transistors and flexible devices based on curved molecules are constructed and the charge transport property are obtained.The main contents are as follows:1.One-dimensional assembly properties and charge transport properties of a trichalcogenasumanene.Se-doped sumanene was a bowl-shaped structure with concave surface and convex surface.The molecule formed columnarπ-πstacking in the crystal structure and self-assembled into 1D micro-crystals easily.A highly ordered columnarπ-πstacking structure along the long axes of the crystal were found,which was one of the highest mobilities forπ-bowls.This finding provided a useful guide for the design of novel molecule bowls.2.Two-dimensional assembly and anisotropic charge transport properties of a trichalcogenasumanene.By extension of the conjugation length of the core of theπ-bowl,large-area two-dimensional crystals were obtained successfully.The anisotropic charge transport property along theπ-πstacking direction and the direction perpendicular to theπ-πstacking has been studied.Large charge transport anisotropy was found.3.Large-area one-dimensional single crystal array and their charge transport property.Sulphur-doped sumanene bowls were used to obtain centimeter-sized single-crystal arrays using a simple drop-casting method.The one-dimensional single crystal array can be obtained easily,irrespective of the substrates,including silicon wafers,ITO and flexible PDMS.Field effect transistors based on the one-dimensional single crystal array showed high performance,the field effect mobility was 0.69 cm²V^-1s^-1.4.Preparation and photo response properties of ultrathin crystalline thin films of a trichalcogenasumanene.By rational molecular design,the ultra-thin two-dimensional organic crystalline film was grown easily by a bottom-up method.The thickness could be as thin as a single molecule layer and the size could reach a millimeter level.The phototransistor based on the crystalline film showed a high switching ratio and high light detection performance.The device exhibited a field-effect mobility of 0.31cm²V^-1s^-1,a switching ratio of over 10⁷,a response of 1.91×10⁴,and a detection rate of 4.39×10¹⁵ Jones.