寡聚噻吩分子薄膜於不同基材表面的位向結構研究及其場效電晶體試製

The Study of molecular orientation of oligothiophene films on various surfaces and the preparation of thin film transistors

江逸凡(Yi-Fan Jiang)

指導教授 ： 陶雨台 ； 吳春桂

國立中央大學/理學院/化學系/碩士(2006年)

摘要

本篇主要分為兩部份，第一部份以寡聚噻吩分子為材料，以真空蒸鍍於金屬、氧化銀與不同自組裝單層膜之基材上，藉由反射式紅外線光譜與X-ray繞射光譜研究寡聚噻吩分子於不同基材上之堆疊位向結構研究。第二部份則是以α-六聯噻吩為材料，於二氧化矽與自組裝單層膜兩種基材表面上製備有機膜，藉由原子力電子顯微鏡與X-ray繞射儀觀察有機膜之表面型態與分子排列；再次於有機膜層上方蒸鍍電極做成有機場效電晶體元件，並藉由參數分析儀之量測分析元件製備的效果。
第一部份的研究結果顯示，寡聚噻吩分子於金屬表面上呈現近似於平躺表面方向堆疊，而於氧化銀與自組裝單層膜上則呈現站立的方式在表面堆疊。第二部份的研究結果發現α-六聯噻吩分子於二氧化矽與自組裝單層膜表面上雖然都是呈現站立的堆積型態，但於自組裝單層膜表面上則有較好的結晶性排列，而在電性量測也發現於在其表面上有較大的載子移動率。另一方面，若將α-六聯噻吩蒸鍍於刷磨之自組裝單層膜表面上，則可在表面上得到覆蓋面積更大之晶體而得到較高的載子遷移率。
此外，我們於第一部份與第二部份均有增加基材升溫的條件，這個條件可以使有機分子產生更好的結晶性排列。

關鍵字

有機場效電晶體

並列摘要

The thesis is divided into two parts. One is about the growth of oligothiophene films by thermal evaporation on metal surfaces and modified metal surfaces such as self-assembled monolayer(SAM) modified silver surface and native silver oxide surface. Their stacking orientation was investigated by reflection absorption IR(RAIR) and Powder X-ray Diffraction spectra (XRD).The other is about
α-sexithiophene thin film on silicon oxide and SAM modified surfaces,as the channel material in the fabrication of organic field effect transistors. The surface morphology and molecular orientation of the thin films were studied by Atomic Force Microscopy(AFM) , Powder X-ray Diffraction (XRD),and then field effect carrier mobilities were measured by Parameter Analyzer.
In the first part of our research, it was observed that the molecules stacked parallel to the clean silver metal surface, but on silver oxide and SAM-modified surface, they stacked perpendicular to the surface. In the second part of our research, although α-sexithiophene molecules oriented perpendicular to the silicon oxide and SAM surfaces, the films on SAM exhibit higher crystallinity and field effect carrier mobility. Interestingly, if the thin film of α-sexithiophene molecule was prepared on rubbed SAM surface,larer grain size and higher field effect carrier mobilities were observed.Furthermore, in all the above cases, we observed that increasing substrate temperature led to more ordered packing and increasing grain size.

並列關鍵字

organic field effect transistors

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