電鍍苯胺類分子在金與矽表面的製備與鑑定

Fabrication and Characterization of Electrografted Aminophenyl Groups at Gold and Silicon Surfaces

林珊

指導教授 ： 洪偉修

國立臺灣師範大學/理學院/化學系/碩士(2009年)

摘要

在本篇論文，是以電化學偶氮化還原的方式在基材表面上電鍍含有苯胺官能基的長碳鏈分子，選用的基材為金基材和矽晶片。藉由電化學，X光-光電子能譜圖，全反射式紅外線光譜來鑑定基材表面上的分子，以及使用CAFM來量測導電特性。
實驗結果顯示，我們成功以電化學電鍍的方式可以在金表面上鍵結長碳鏈苯胺分子；隨著電鍍的樣品分子碳鏈越長，交界處的電阻會呈現指數性的增大，測樣品表面的導電性質時，當施加在探針的力越大，所量測到的電流值就會越大，並且是呈現指數性的劇增。利用Simmons equation計算出的length-dependent decay parameter, β為0.27 Å-1（電壓為± 1.5 V）。將電化學電鍍製成的樣品與以自組裝薄膜方式製成的樣品相比較，會發現以電鍍方式製成的樣品穩定性較好。另外，在矽晶片上以電鍍方式製作的樣品，則是會受到電鍍溶液中溶劑為水溶液的影響，使得矽晶片表面也同時有形成二氧化矽，讓樣品在矽晶片上的導電特性難以被明確測量到。

關鍵字

電鍍 ； 苯胺類分子

並列摘要

In this thesis, we report that the aminophenyl group was grafted at the Au and Si surfaces with electrochemical deposition via the reduction of aminophenyl monodiazonium cations. The presence of the aminophenyl group on the surface was demonstrated with cyclic voltammetry (CV),
X-ray photoelectron spectroscopy (XPS), and attenuated total reflection infrared spectroscopy (ATR-IR). The conductive atomic force microscopy (CAFM) was used to record electrical properties of the aminophenylgrafted
surfaces.
The CAFM was employed to measure the junction resistance
between the probe tip and the molecular film. Our experimental results indicated that the junction resistance increased exponentially with the alkyl chain length. The junction resistance decreased with the increase of the load force applied to the tip. The length-dependent decay parameter, β,was found to be 0.27 Å-1 which was independent of applied bias (over a voltage range of ± 1.5 V). The aminophenyl-grafted Au surface exhibited a surface electrical resistance comparable to the self-assembled ODT
monolayer. The aminophenyl-graft Si surface showed the different electrical behaviors from the corresponding Au surface because the Si oxides were inevitably formed during the electrical deposition in aqueous solution.

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