Interaction between Post-Graphene Group-IV Honeycomb Monolayers and Metal Substrates: Implication for Synthesis and Structure Control

Abstract

Beyond graphene, other group IV monolayers with honeycomb lattice, including silicene, germanene, and stanene, have attracted much attention due to their peculiar physical properties and potential applications in future electronic devices. However, since sp3 hybridization is more favorable than sp2 hybridization for Si, Ge, and Sn, these group IV monolayers have to be stabilized by metal surfaces during epitaxial synthesis. Using systematical first-principles calculations, here we investigate the interactions between these monolayers and various metal surfaces, i.e., Ag(111), Ir(111), Pt(111), Al(111), Au(111), and Cu(111). STM images, charge density difference, and partial density of states of these monolayer/metal systems have been calculated and discussed. In combination with the known experimental facts, we find that a moderate strength of interaction at 0.6–0.7 eV/atom is beneficial for the epitaxial growth of silicene and germanene without too much buckling or in-plane distortion. We further propose...