單晶相石墨烯製備與特性分析

Characteristics analysis and synthesis of hexagonal graphene crystals

朱彥霖(Yen-Lin Chu)

指導教授 ： 陳昇暉

國立中央大學/理學院/光電科學與工程學系/碩士(2014年)

摘要

石墨烯，特殊的二維結構使其具有許多優異的特性，如具備優異的電性及極高的光學穿透率，極有潛力應用於透明導電膜。製備石墨烯常用的多晶銅箔以化學氣相沉積法為主，但此方法所製備之石墨烯會因為其晶粒間旋轉角的不同，使晶界缺陷所帶來的散射問題，影響其導電性。
本論文以單晶向銅膜(111)成長方向一致之石墨烯，並以ImageJ影像處理與分析軟體，對SEM所拍攝之圖形進行快速傅立葉轉換，分析石墨烯晶粒旋轉角度，並以拉曼映像分析其晶粒間接合處之缺陷及石墨烯結晶品質，並將之與於銅箔生長之石墨烯進行比較，以及利用四點探針量測其片電阻值。使用單晶相銅膜(111)成長之石墨烯，波長350 nm~800 nm的平均穿透率可達97.52%，片電阻值為534Ω/□，且成長之石墨烯無明顯雙層，與銅箔成長相比，其拉曼量測上有較好的結晶性及較少的缺陷訊號，且能減少石墨烯晶界之缺陷，並有較好的光穿透及電性。

關鍵字

單晶相 ； 石墨烯 ； 化學氣相沉積法

並列摘要

Graphene, a two-dimensional monolayer of sp2 bonded carbon atoms, has attracted since it was discovered in 2004 because of its unique properties. It is a great candidate for flexible transparent conductive films because of its excellent electrical conductivity and high optical transmittance. However, the grain boundaries occurred when graphene synthesized on the polycrystalline Cu foil by using chemical vapor deposition (CVD). The polycrystalline Cu grains lead to the different orientation of graphene domains owing to the lattice constant mismatch.
In this study, the graphene domains with a consistency of orientation were synthesized on the single crystal Cu (111) thin film. Fast Fourier transform was employed to analyze the orientation of hexagonal graphene domains. The resulting sheet resistance of monolayer graphene reaches the values as low as 534Ω/□ and the average transmittance is 97.52 % in the visible light region. Furthermore, through the Raman mapping, the defect signal of graphene boundaries grown on Cu polycrystalline was larger than the graphene grown on the Cu film.

並列關鍵字

graphene ； CVD ； single orientation

參考文獻

[9] 吳盈樺, "隨機位能對單層石墨烯和石墨烯島嶼電子特性," 國立成功大學, 碩士論文, 2012.

[1] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, et al., "Electric field effect in atomically thin carbon films," Science, vol. 306, pp. 666-9, 2004.

[2] K. I. Bolotin, K. Sikes, Z. Jiang, M. Klima, G. Fudenberg, J. Hone, et al., "Ultrahigh electron mobility in suspended graphene," Solid State Communications, vol. 146, pp. 351-355, 2008.

[4] R. Murali, Y. Yang, K. Brenner, T. Beck, and J. D. Meindl, "Breakdown current density of graphene nanoribbons," Applied Physics Letters, vol. 94, pp. 243114, 2009.

[5] C. Lee, X. Wei, J. W. Kysar, and J. Hone, "Measurement of the elastic properties and intrinsic strength of monolayer graphene," Science, vol. 321, pp. 385-388, 2008.