Electronic Structures and Structural Evolution of Hydrogenated Graphene Probed by Raman Spectroscopy

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• 作者：Zhiqiang Luo ; Ting Yu ; Zhenhua Ni ; Sanhua Lim ; Hailong Hu ; Jingzhi Shang ; Lei Liu ; Zexiang Shen ; Jianyi Lin
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：February 10, 2011
• 年：2011
• 卷：115
• 期：5
• 页码：1422-1427
• 全文大小：935K
• 年卷期：v.115,no.5(February 10, 2011)
• ISSN：1932-7455

文摘

The electronic structures and structural evolution of hydrogenated graphene are investigated by Raman spectroscopy with multiple excitations. The excitation energy dependent saturation effect on the ratio of integrated intensities of D and G modes (I_D/I_G) is revealed and interpreted by a D band active model with D band Raman relaxation length and photoexcited electron/hole wavelength as critical length scales. At low hydrogen coverage, the chemisorbed H atoms behave like defects in sp² C鈺怌 matrix; for a high hydrogen coverage, the sp³ C鈭扝 bonds become coalescent clusters resulting in confinement effect on the sp² C domains. Electronic structure changes caused by varying hydrogen coverage are evidenced by excitation energy dependent red shift of D and 2D bands. Our results provide a useful guide for developing applications of hydrogenated graphene as well as for using Raman spectroscopy for quick characterization in further exploring other kinds of graphene derivatives.