Epitaxial growth of elemental 2D materials: What can we learn from the periodic table?

Abstract Recent achievements in the fabrication of two-dimensional (2D) materials by molecular beam epitaxy have demonstrated that surface alloys are critical intermediates for either layer by layer or segregation growth. The resulting films show a homogenous growth mode that strongly depends on the lattice and properties of surface alloys. Learning from the periodic table, we address the importance of surface alloys in the heterogeneous growth of 2D materials. We demonstrate basic rules in the formation of surface alloys that are correlated with their periodic properties. We highlight the possibility of using 2D topological insulators as the substrates to accomplish quasifreestanding monolayers. Finally, we assess the current status and challenges of binary 2D materials and discuss prospects of their fabrication via surface alloy processes.