Interactions between epitaxial graphene grown on Si- and C-faces were investigated using Raman imaging and tip-enhanced Raman scattering (TERS). In the TERS spectrum, which has a spatial resolution exceeding the diffraction limit, a D band was observed not from graphene surface, but from the edges of the epitaxial graphene ribbons without a buffer layer, which interacts with SiC on the Si-face. In contrast, for a graphene micro-island on the C-face, the D band disappeared even on the edges where the C atoms were arranged in armchair configurations. The disappearance of the edge chirality via combination between the C atoms and SiC on the C-face is responsible for this phenomenon. The TERS signals from the C-face were weaker than those from the Si-face without the buffer layer. On the Si-face with a buffer layer, the graphene TERS signal was hardly observed. TERS enhancement was suppressed by interactions on the edges or by the buffer layer between the SiC and graphene on the C- or Si-face, respectively.

中文翻译：

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EXPRESS：使用拉曼成像和尖端增强拉曼散射研究在 4H-SiC 的 Si 和 C 面上生长的外延石墨烯之间的相互作用

使用拉曼成像和尖端增强拉曼散射 (TERS) 研究了在 Si 和 C 面上生长的外延石墨烯之间的相互作用。在空间分辨率超过衍射极限的 TERS 光谱中，D 带不是从石墨烯表面观察到的，而是从没有缓冲层的外延石墨烯带的边缘观察到的，缓冲层与 Si 面上的 SiC 相互作用。相比之下，对于 C 面上的石墨烯微岛，即使在 C 原子以扶手椅结构排列的边缘上，D 带也消失了。通过 C 原子和 C 面上的 SiC 之间的结合，边缘手性的消失是造成这种现象的原因。C面的TERS信号比没有缓冲层的Si面的信号弱。在带有缓冲层的 Si 面上，几乎观察不到石墨烯 TERS 信号。TERS 增强分别被边缘上的相互作用或 C 面或 Si 面上的 SiC 和石墨烯之间的缓冲层抑制。