The investigation of graphene as a protective coating for different materials has been an area of active research for well over a decade. However, graphene’s ability to protect clean, reconstructed silicon from ambient gases has remained uninvestigated. Here, we describe the use of a clean ultrahigh vacuum transfer method to deposit graphene onto the Si(111)-7 × 7 reconstruction. Using a combination of X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM), we confirmed the successful transfer of graphene onto the surface. We then exposed the graphene-protected surface to 120 L of ambient air in the vacuum chamber and found that although the reconstruction is destroyed on unprotected terraces, clean and ordered silicon can be imaged through the transferred graphene. Exposing the sample to ambient air at atmospheric pressure for 2 days produces a strong signature of oxidation in XPS, and STM images revealed that although graphene can still be identified, the regions beneath the graphene appear amorphous. This work demonstrates that graphene provides some protection against the oxidation of Si(111)-7 × 7 by air, but that this protective ability is not sufficient to forestall oxidation during prolonged exposure to atmospheric conditions.

中文翻译：

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在超高真空下将石墨烯剥离到 Si（111）-7 × 7 上，可提供一些保护，防止暴露在空气中


十多年来，石墨烯作为不同材料的保护涂层的研究一直是一个积极研究的领域。然而，石墨烯保护清洁、重构硅免受环境气体影响的能力仍未得到研究。在这里，我们描述了使用干净的超高真空转移方法将石墨烯沉积到 Si（111）-7 × 7 重建上。结合使用 X 射线光电子能谱 （XPS） 和扫描隧道显微镜 （STM），我们证实了石墨烯成功转移到表面上。然后，我们将石墨烯保护的表面暴露在真空室中的 120 L 环境空气中，发现虽然重建在未受保护的露台上被破坏，但可以通过转移的石墨烯对干净有序的硅进行成像。将样品暴露在大气压下的环境空气中 2 天，XPS 中会产生强烈的氧化特征，STM 图像显示，尽管仍然可以识别石墨烯，但石墨烯下方的区域似乎是无定形的。这项工作表明，石墨烯对 Si（111）-7 × 7 被空气氧化提供了一定的保护，但这种保护能力不足以防止长时间暴露在大气条件下的氧化。