Mechanism of remote epitaxy of stanene on Cu(111) substrate through monolayer graphene linking

Abstract

Graphene-coated substrates have a significant effect on regulating the commensurate epilayer growth of ionic thin-films, which has demonstrated that the polarity of atomic binding in ionic-bonded materials is strong enough to penetrate through a few-layer graphene, but that from the covalent-bonded material is screened even by a monolayer graphene (MLG). However, recent studies have demonstrated that the covalent-bonded stanene film can also be obtained by the remote heteroepitaxy on the monolayer graphene-covered Cu(111) substrate. In this work, we use first-principles calculations to uncover the microscopic mechanism of the unusual remote interactions, which facilitate the Sn adatom growth on the MLG-covered Cu substrate. Our calculations suggest that the lattice sites of MLG determine the adatom registry and provide an essential mediator role in the extended adatom-linking-substrate interactions, whereas the Cu substrate under the MLG reinforces the adsorption on the entire surface by the extended hybridization of MLG/Cu(111) interfacial states with the Sn adatom localized states. This finding provides a novel insight into the remote epitaxial mechanism of 2D films on the MLG-covered metal substrates, which opens the opportunity in the field of vdW (van der Waals) epitaxial of low-dimensional element crystalline and their transferable integration.