Nucleation preference and lateral growth of monolayer tin disulfide on graphene

Abstract

Two-dimensional (2D) heterostructures have attracted significant interest in recent years due to their novel physics and great potential in various applications. However, the achievement of controllable synthesis of large-scale 2D heterostructures remains a great challenge. Here, we demonstrate the successful van der Waals epitaxial growth of monolayer SnS₂ with nearly complete coverage on graphene by the method of chemical vapor deposition. The investigation reveals that the nucleation density of SnS₂ on graphene undergoes notable variations stemming from the presence of amorphous carbons. The lateral growth and morphology evolution of SnS₂ nuclei are illustrated by the theoretical studies on the adsorption and migration of precursors on graphene. On the basis of these results, an improved process is proposed to realize the uniform nucleation and high-coverage growth of SnS₂ monolayers. The findings offer profound insights into the growth mechanism of van der Waals epitaxy, holding significant implications for the practical utilization of two-dimensional heterostructures.