劉陵崗臺灣大學：化學研究所朱傑Chu, ChiehChiehChu2007-11-262018-07-102007-11-262018-07-102007http://ntur.lib.ntu.edu.tw//handle/246246/52025我們成功合成出以quinoxaline為主體架構，並帶有含氟取代及不含氟取代長碳鏈之液晶材料。利用熱重量分析儀和循環伏特安培儀來確認其熱穩定性和還原電位，並以偏光顯微鏡、熱差式掃描卡計儀、及變溫粉末X光繞射儀來鑑定其中間相。這些具液晶相的分子成膜在矽基板上或是以自組裝薄膜修飾後的矽基板上時，其排列方向及表面型態，分別藉由粉末X光繞射儀和原子力顯微鏡來研究。我們成功利用親氟及斥氟的作用力來使分子能夠以垂直排列的方式在PFTS修飾的矽基板表面上，這提供了一個新的準則來設計能應用在有機場效電晶體的有機半導體材料。Three series of quinoxaline-based liquid crystal materials with or without semifluorinated alkyl chains have been successfully synthesized. Their thermal stabilities, reduction potentials, and mesophase characteristics have been examined by TGA, CV, POM, DSC, and temperature-dependent PXRD, respectively. The molecular orientation and their film morphology on the substrate (SiO2/Si) with or without SAMs also have investigated by PXRD and AFM. The control of molecular orientation, to be perpendicular to the substrate treated with PFTS via fluorophilic/fluorophobic interaction, has been achieved. This method provides a new molecular design principle enabling desired molecular alignment of organic semiconducting materials for organic field-effect transistors.Contents I List of Figures III List of Tables VII Abstract VIII Chapter One Introduction 1 1.1 Preface 1 1.2 OFET geometry and operation 1 1.3 Electronic properties of organic materials 5 1.4 N-type materials 6 1.5 Discotic liquid crystals 14 1.6 SAMs 17 1.7 Fluorophobic effect 18 1.8 Motivation of study 19 Chapter Two Experimental 22 2.1 Reagents 22 2.2 Instruments 22 2.3 Sample preparation 24 2.4 Synthesis 25 2.4.1 Preparation of precursors 25 2.4.2 Synthesis of target compounds 32 Chapter Three Results and Discussion 46 3.1 Synthesis 46 3.2 Thermal analysis and electronic properties 46 3.3 Molecular packing 49 3.3.1 Liquid crystalline properties of DQ-, QP-, and Q-Cn 49 3.3.2 Influence of molecular packing by introducing semifluorinated alkyl chains 62 3.3.3 The resulting liquid crystalline phases by incorporating semifluorinated and hydrocarbon alkyl chains 67 3.4 Investigation of molecular orientation and film morphology 75 3.5 OFET devices 81 Chapter Four Conclusions 83 References 85 Appendix A 89 Appendix B 93 Appendix C 96 Appendix D 985587361 bytesapplication/pdfen-US負電型有機場效電晶體盤狀液晶N-TypeOFETsDiscotic Liquid Crystalsthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/52025/1/ntu-96-R94223054-1.pdf