透過電化學嵌入的石墨烯剝離和摻雜

Exfoliation and Doping of Graphene through Electrochemical Intercalation

蔡尚霖(Shang-Lin Tsai)

指導教授 ： 謝雅萍

國立中正大學/工學院/光機電整合工程研究所/碩士(2014年)

摘要

近幾年來，石墨烯被全世界學者們研究，因為它有許多獨特的優點，高穿透、低電阻值、高遷移率和可饒式，這對半導體應用上有極大影響，石墨烯將成為重要的材料。目前已經有利用化學剝離法，來剝離石墨片並獲得石墨烯，但是此方法必須先氧化石墨烯，之後在高溫還原，這些步驟非常複雜，不適合廣泛應用。
現今大多使用電化學剝離法來獲取石墨烯，此方法低成本、快速且製造容易，藉由電解液中的石墨電極被離子嵌入、膨脹，然後調變電壓參數使之剝離，進而產生石墨烯，是個非常有效率的方法，然而，對於電化學剝離和嵌入的機制卻絲毫不知，因此這將是本實驗的重要議題。
首先設計一套可以了解嵌入過程的實驗，透過X光單晶繞射儀觀察石墨片被電解液嵌入過後的結構，X射線光電子能譜儀和表面能階分析來了解石墨片被電解液嵌入過後的特性，拉曼分析則顯示出，最佳的剝離步驟可能增加石墨烯的品質和摻雜的現象，使用原子力顯微鏡來觀察剝離後石墨烯厚度的變化情形，然後藉著拉曼位移差以及功函數來計算出摻雜濃度，最後可以獲得穿透度70%片電阻值2K左右的石墨烯薄膜。
利用此套實驗，可以很容易了解電化學剝離和嵌入的原因，以及摻雜將會影響電性，這對於石墨烯在未來商業上的應用，如：導電薄膜、電池或透明電極，會有很大的幫助。

關鍵字

石墨烯 ； 電化學剝離 ； 嵌入

並列摘要

In the last few years graphene has become an important material in many application areas due to its unique properties such as transparency, high thermal conductivity, great mechanical resistance and excellent electronic conduction. To fulfill the requirements from industrial applications, a scalable production method is needed. Common fabrication methods rely on the chemical exfoliation of graphite which typically requires many complicated process steps including oxidation of graphite and high temperature reduction.
Electrochemical exfoliation have been demonstrated as a simple, low cost and fast method to exfoliate graphite. The graphite electrode can be electrochemically charged and expanded in an aqueous electrolyte. The electrochemical exfoliation process shows advantages of scalability, and minimal use of etching chemicals. However, the quality of exfoliated graphene and the mechanism of electrochemical exfoliation and intercalation is still not well understood.
Therefore, We have a detailed analysis of the intercalation process. Through X-ray diffraction observe the structure of the graphite intercalation compounds. X-ray photoelectron spectroscopic and EDS were used to characterize the graphite intercalation compounds. Raman analysis show that optimized exfoliation steps can increase the graphene quality and doping phenomenon.
This work can help improve the commercial application of graphene as conductive films, battery electrodes or transparent electrode.

並列關鍵字

electrochemical exfoliation ； Intercalation ； graphene

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