鐵鎳合金系統製備大面積石墨膜之研究

The Study of Large Area Graphite Film Preparation Based on Fe-Ni Alloy System

許倍誌(Pei-Chih Hsu)

指導教授 ： 徐開鴻

國立臺北科技大學/工程學院/材料科學與工程研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00460

摘要

石墨烯(Graphene)，為一種二維的碳結構，是近幾年來深受到關注的薄膜材料，在優越的化學穩定性、導電特性及機械性質下，未來將在能源材料、光學顯示器等領域受到重視。
本研究利用高溫高壓合成鑽石中過渡金屬對於碳原子催化之原理，選擇鐵及鎳過渡金屬進行實驗，碳來源採用天然石墨粉末，在高溫真空狀態下，當合金到達液相狀態時，石墨因過渡金屬液相催化的機制下自我修復重組，在合金的表面上成長出石墨層。透過改變合金及石墨的比例、持溫的時間，在最佳的參數下，可以成功的製備出連續狀且大面積(公分)的石墨層。
為了了解石墨層的成長機制、性質及厚度，將試片在石墨層分離前及分離後進行觀察，利用光學顯微鏡、掃描式電子顯微鏡、拉曼光譜儀及X光繞射光譜儀進行分析。在光學顯微鏡的觀察，可以從試片的剖面得知石墨的生長及其分佈，發現在不同的配比下，石墨有明顯的變化趨勢。探討成長機制，在最佳的製程參數中，觀察到石墨層的厚度在1~3 μm間。利用稀酸性水溶液將石墨層從合金界面分離，轉移至玻璃基材上，以利於各量測及分析的進行。利用此製程製備的石墨層厚度與皺摺是目前所面臨的問題，若能有效的減少厚度且不破壞形貌以及消除皺摺，對於未來石墨烯的應用將更有利於發展。

關鍵字

石墨烯 ； 高定向熱解石墨 ； 鐵鎳合金 ； 液相催化

並列摘要

Graphene is a two-dimensional carbon structure. As a film material, it has been drawing attentions over the past few years due to its excellent chemical stability, electrical and mechanical properties, which make graphene a promising energy and optical displays materials.
This study is based on the mechanism of transition metal catalyzed graphite to diamond transition under high pressure and temperature. Iron and nickel transition metal powders are adopted to react with graphite powders in high temperature vacuum sintering furnace. After melting, the graphite flakes can be catalytically mended together by the transition metal alloy. This process is self assembling and self healing, so graphite layers can be formed on the surface of the ingot. With optimal alloy/graphite ratios and holding time, large area graphite film can be successfully prepared.
The formation mechanism, properties and thickness of the graphite film before and after separation are analyzed by optical microscopy, scanning electron microscopy, Raman spectroscopy and X-ray diffraction spectrometer. The cross-sectional metallographic observation of bulk specimen by an optical microscope shows the distribution and variation of graphite under various ratios, which offers informations of graphite formation mechanism. With optimal experiment parameters, the graphite layer thickness is observed to be 1 ~ 3 μm. Separation process is carried out by etching the interface between graphite layer and alloy ingot with acid liquor. The graphite films are retrieved and mounted on a SiO2 substrate for subsequent analysis. The thickness of the graphite film prepared in this process still needs improving. If it is effectively lowered without influencing the morphology, there will be more potential for the development of applications.

並列關鍵字

graphene ； HOPG ； Fe-Ni Alloy ； liquid-phase catalysis

參考文獻

[3] P. Blake, P. D. Brimicombe, R. R. Nair, T. J. Booth, D. Jiang, F. Schedin, L. A. Ponomarenko, S. V. Morozov, H. F. Gleeson, E. W. Hill, A. K. Geim and K. S. Novoselov, “Graphene-Based Liquid Crystal Device”, Nano Lett., vol.8, 2008, pp.1704–1708.

[47] A. C. Ferrari, J. C. Meyer, V. Scardaci, C. Casiraghi, M. Lazzeri, F. Mauri, S. Piscanec, D. Jiang, K. S. Novoselov, S. Roth and A. K. Geim, “Raman Spectrum of Graphene and Graphene Layers”, Physical review letters., vol.97, 2006, p.187401.

[2] V. C. Tung, L. M. Chen, M. J. Allen, J. K. Wassei, K. Nelson, R. B. Kaner and Y. Yang, “Low-Temperature Solution Processing of Graphene−Carbon Nanotube Hybrid Materials for High-Performance Transparent Conductors”, Nano Lett., 2009, pp.1949-1955.

[4] X. Wang, L. Zhi and K. Mullen, “Transparent, Conductive Graphene Electrodes for Dye-Sensitized Solar Cells”, Nano Lett., vol.8, 2008, pp.323–327.

[5] S. Biswas and L. T. Drzal, “A Novel Approach to Create a Highly Ordered Monolayer Film of Graphene Nanosheets at the Liquid−Liquid Interface”, Nano Lett., vol.9, 2009, pp.167–172.