Vertical heterostructures based on two-dimensional (2D) materials have attracted widespread interest for their numerous applications in electronic and optoelectronic devices. Herein, we report the direct construction of an abnormal graphene/ReSe₂ stack on Au foils by a two-step chemical vapor deposition (CVD) strategy. During the second growth stage, monolayer ReSe₂ is found to preferentially evolve at the interface between the first-grown graphene layer and the Au substrate. The unusual stacking behavior is unraveled by in-situ “cutting open” the upper graphene from the defects to expose the lower ReSe₂ using scanning tunneling microscopy (STM). From combination of these results with density functional theory calculations, the domain boundaries and edge sites of graphene are proposed to be adsorption sites for Re and Se precursors, further facilitating the growth of ReSe₂ at the van der Waals gap of graphene/Au. This work hereby offers an intriguing strategy for obtaining vertical 2D heterostructures featured with an ultra-clean interface and a designed stacking geometry.

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基于二维（2D）材料的垂直异质结构因其在电子和光电设备中的众多应用而引起了广泛的关注。本文中，我们报告了通过两步化学气相沉积（CVD）策略在Au箔上直接构造异常石墨烯/ ReSe ₂堆栈的方法。在第二个生长阶段，发现单层ReSe ₂在第一个生长的石墨烯层和Au衬底之间的界面处优先演化。通过从缺陷中就地“切开”上层石墨烯以暴露下层ReSe ₂来揭示异常的堆叠行为使用扫描隧道显微镜（STM）。通过将这些结果与密度泛函理论计算相结合，提出石墨烯的畴边界和边缘位点是Re和Se前体的吸附位点，从而进一步促进了ReSe ₂在石墨烯/ Au的范德华间隙处的生长。因此，这项工作为获得具有超净界面和设计的堆叠几何形状的垂直2D异质结构提供了一种引人入胜的策略。

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