Top or underneath? Revealing the structure of multilayer graphene domains with atomic force microscopy and theoretical analysis
Top or underneath? Revealing the structure of multilayer graphene domains with atomic force microscopy and theoretical analysis
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DOI：
10.1016/j.carbon.2015.11.072
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发表时间：
2016-04
期刊：
影响因子：
10.9
通讯作者：
Wei Huang;Zhi-fei Liu;Zhi-Yong Yang
中科院分区：
文献类型：
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作者：
Wei Huang;Zhi-fei Liu;Zhi-Yong Yang
通过原子力显微镜和理论分析揭示了铜箔上多层石墨烯域的结构。力显微镜的相位图像能够将石墨烯域与铜箔的裸露区域分离。此外，相位图像能够区分不同的石墨烯层和结构。例如，一些小的石墨烯层表现出比周围的单层区域更暗的相位对比度，而其他小层相对于周围的单层区域具有更亮的对比度。然后，我们继续确定几层石墨烯域是婚礼蛋糕（WC）还是倒置婚礼蛋糕（IWC）结构。通过逐层法在Cu上制备了具有人造WC、IWC和三明治结构的石墨烯样品。根据人工结构的结果，我们可以知道，生长样品中显示较暗对比度的区域对应于 WC 结构，而显示明亮对比度的区域是 IWC 域。理论讨论表明，Cu 或相应石墨烯层上耗散的不同能量是造成相衬变化的原因。
The structure of multilayer graphene domains on Cu foil is revealed with atomic force microscopy and theoretical analysis. The phase images of force microscopy enable the separation of the graphene domains from the naked areas of Cu foil. Furthermore, the phase images enable the discrimination of the different graphene layers and structures. For example, some of small graphene layers show a darker phase contrast than the surrounding single layer districts while other small layers have a brighter contrast with respect to the surrounding single layer areas. Then, we proceed to determine whether the few-layer graphene domains are wedding cake (WC) or inverted wedding cake (IWC) structures. The graphene samples with the artificial WC, IWC and sandwich structure were fabricated on Cu through layer by layer method. Based on the results of the artificial structures, we can know that the areas showing darker contrast in the as-grown samples correspond to the WC structure and the areas showing bright contrast are the IWC domains. Theoretical discussions disclose that the different energy dissipated on Cu or the respective graphene layer is responsible for the variation of the phase contrast.