We demonstrate the fabrication of an ultrathin gallium film, also known as gallenene, beneath epitaxial graphene on 6H-SiC under ambient conditions triggered by liquid gallium intercalation. Gallenene has been fabricated using liquid metal intercalation, achieving lateral intercalation and diffusion of Ga atoms at room temperature on square centimeter areas limited only by the graphene samples’ size. The stepwise self-propagation of the gallenene film below the epitaxial graphene surface on the macroscopic scale was observed by optical microscopy shortly after the initial processing without further physical or chemical treatment. Directional Ga diffusion of gallenene occurs on SiC terraces since the terrace steps form an energetic barrier (Ehrlich-Schwoebel barrier), retarding the gallenene propagation. The subsequent conversion of the epitaxial graphene into quasi-free-standing bilayer graphene and the graphene-gallenene heterostack interactions have been analyzed by x-ray photoelectron spectroscopy and Raman measurements. The results reveal an alternative approach for the controlled fabrication of wafer-scale gallenene as well as for two-dimensional heterostructures and stacks based on the interaction between liquid metal and epitaxial graphene.

中文翻译：

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外延石墨烯的液态金属嵌入：在环境条件下通过镓的自蔓延制造大面积的镓烯层

我们证明了在由液态镓嵌入触发的环境条件下，在6H-SiC上外延石墨烯下方制造超薄镓膜（也称为镓）的过程。使用液态金属插层制造加仑烯，从而在室温下在仅受石墨烯样品尺寸限制的平方厘米区域实现Ga原子的横向插层和扩散。在初始加工后不久，无需进一步的物理或化学处理就可通过光学显微镜观察到宏观尺度上外延石墨烯表面下方的加仑烯膜的逐步自蔓延。SiC台阶上发生了Ga烯的定向Ga扩散，因为台阶台阶形成了高能势垒（Ehrlich-Schwoebel势垒），阻碍了Galenene的扩散。通过x射线光电子能谱和拉曼测量分析了外延石墨烯随后转化为准自立式双层石墨烯以及石墨烯-亚硒烯异质堆叠相互作用。结果揭示了基于液态金属和外延石墨烯之间相互作用的晶片级加仑烯的受控制造以及二维异质结构和堆叠的替代方法。