雙炔基分子於不同基材表面薄膜結構及其聚合反應性研究與其場效電晶體試製

Structure and polymerization properties of molecular films of diacetylenic derivatives on various surfaces: attempted application in field effect transistors

廖凱貞(Kai-Chen Liao)

指導教授 ： 陶雨臺

國立中央大學/理學院/化學系/碩士(2007年)

摘要

本篇研究主要分為兩個部分，第一個部分為雙炔基有機酸分子(diacetylenic acid) 與雙炔基三氯矽烷分子(diacetylenic trichlorosilane)分別在銀、鋁表面與二氧化矽表面的自組單分子薄膜，藉由紅外線光譜分析與拉曼光譜、近緣X光吸收微組態光譜(NEXAFS)和UV吸收光譜分析結構及其topochemical聚合反應性。第二部分則是以真空蒸鍍方式將雙炔基有機酸蒸鍍於二氧化矽表面、壬烷基三氯矽烷(NTS)單層膜及刷磨過的壬烷基三氯矽烷單層膜上，藉由紅外線光譜、原子力顯微鏡及X光繞射儀觀察有機膜之表面型態與分子排列；並以之為通道材料製成有機場效電晶體元件，量測與評估元件的效果。
第一部分的研究結果顯示，照光聚合反應僅發生於銀表面的雙炔基有機酸單分子層，可能是該分子在銀和鋁的表面鍵結型態不同，造成分子間距離與分子鏈傾斜程度的差異。而NEXAFs分析結果發現，在表面經刷磨的處理會有利於分子傾向某一方向的排列。另外，在二氧化矽表面測量聚雙炔基矽烷自組裝單分子膜不同方向的電性，顯示在刷膜方向與源極-汲極方向平行時，其導電性性質比垂直方向電流大108倍，電流可達10-4A。第二部份的研究中，藉由紅外線光譜和原子力顯微鏡表面分析，我們發現雙炔基有機酸在二氧化矽表面和壬烷基三氯矽烷單層膜上應是以氫鍵結合的雙體站立的方式在表面堆疊；另外，當基材溫度增加，分子在表面的移動性提高，影響蒸鍍薄膜形貌與晶粒大小。在三種表面中，唯有在刷磨的壬烷基三氯矽烷單層膜上，刷磨方向與源極-汲極方向平行時，會有較好的場效現象，其他則無。

關鍵字

有機場效電晶體 ； 自組裝薄膜 ； 雙炔基分子

並列摘要

The thesis is divided into two parts. One is about self-assemble monolayer(SAM) of diacetylenic acid on silver and aluminum and diacetylenic trichlorosilane on silicon oxide surface. Their packing structure and topochemical polymerization behavior were investigated by Infraed Spectroscopy (IR), Raman Spectroscopy, Ultraviolet-visible spectroscopy(UV) and Near Edge X-ray Absorption Fine Structure Spectroscopy(NEXAFS). The second part is about the deposition and polymerization of diacetylenic acid films on silicon oxide surface and SAM-modified silicon oxide surfaces. These films were studied by IR, UV, Atomic Force Microscopy(AFM), Powder X-ray Diffraction (XRD). Field effect transistors based on these films as channel material were prepared and evaluated.
In the first part, topochemical polymerization was observed only for SAMs prepared on Ag surface, not on Al surface, probably due to different intermolecular distances and extent of chain tilt of diacetylenic acid adsorbed on two surfaces. Rubbing of the monolayer resulted in in-plane orientation preference in the packing. The electrical property of self-assemble monolayer of diacetylenylsilane on silicon oxide surface was measured to exhibit orientation-dependent conductance such that the conductivity along the rubbing direction is 108 times higher than that perpendicular to the rubbing direction.
In the second part, the deposited film of diacetylenic acid consists of layers of H-bonded dimmers oriented nearly perpendicular to the surface. The morphology depends strongly on the substrate temperature. FET devices based on the diacetylenic acid films as channel material showed gating effect only for films deposited on rubbed NTS-SiO2 surface at 50?C along the rubbing direction.

並列關鍵字

polydiacetylene ； self-assemble monolayer ； topochemical polymerization

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