Van der Waals heteroepitaxy of air stable quasi-free standing silicene layers on CVD epitaxial graphene/6H-SiC

Zouhour Ben Jabra; Mathieu Abel; Filippo Fabbri; Jean-Noel Aqua; Mathieu Koudia; Adrien Michon; Paola Castrucci; Antoine Ronda; Holger Vach; Maurizio De Crescenzi; Isabelle Berbezier

arXiv · 2203.08183

Van der Waals heteroepitaxy of air stable quasi-free standing silicene layers on CVD epitaxial graphene/6H-SiC

Zouhour Ben Jabra·Mathieu Abel·Filippo Fabbri·Jean-Noel Aqua·Mathieu Koudia·Adrien Michon·Paola Castrucci·Antoine Ronda·Holger Vach·Maurizio De Crescenzi·Isabelle Berbezier

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Abstract

Graphene, consisting of an inert, thermally stable material with an atomically flat, dangling bond-free surface is by essence an ideal template layer for van der Waals heteroepitaxy of two-dimensional materials such as silicene. However, depending on the synthesis method and growth parameters, graphene (Gr) substrates could exhibit, on a single sample, various surface structures, thicknesses, defects, and step heights. These structures noticeably affect the growth mode of epitaxial layers, e.g. turning the layer-by-layer growth into the Volmer-Weber growth promoted by defect-assisted nucleation. In this work, the growth of silicon on chemical vapor deposited epitaxial Gr (1 ML Gr/1ML Gr buffer) on 6H-SiC(0001) substrate is investigated by a combination of atomic force microscopy (AFM), scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Raman spectroscopy measurements. It is shown that the perfect control of full-scale almost defect-free 1 ML Gr with a single surface structure and the ultra-clean conditions for molecular beam epitaxy (MBE) deposition of silicon represent key prerequisites for ensuring the growth of extended silicene sheets on epitaxial graphene.

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Zouhour Ben Jabra, Mathieu Abel, Filippo Fabbri, Jean-Noel Aqua, Mathieu Koudia, Adrien Michon, Paola Castrucci, Antoine Ronda, Holger Vach, Maurizio De Crescenzi, Isabelle Berbezier. 2022-03-15. Van der Waals heteroepitaxy of air stable quasi-free standing silicene layers on CVD epitaxial graphene/6H-SiC. https://arxiv.org/abs/2203.08183

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