Influence of chemical interaction at the lattice-mismatched h-BN/Rh(111) and h-BN/Pt(111) interfaces on the overlayer morphology

The atomic and electronic structure of the lattice-mismatched h-BN/Pt(111) and h-BN/Rh(111) interfaces formed by pyrolitic reactions with vaporized borazine has been studied by low-energy electron diffraction, scanning tunneling microscopy, x-ray-absorption spectroscopy, and core-level and valence-band photoemission. It has been found that on Pt(111), h-BN forms a nearly flat monolayer, insignificantly corrugated across the supercell. On Rh(111), h-BN grows in form of a nanomesh, as originally observed by Corso [Science 303, 217 (2004)]. The structural difference between the h-BN/Pt(111) and h-BN/Rh(111) interfaces is associated with the strength of chemical interaction between h-BN and the substrate surface. A stronger orbital hybridization on Rh(111) results in a stronger attraction of the monolayer to the metal surface at favorable adsorption sites resulting in a highly corrugated structure (nanomesh). It has been shown that the electronic structure of the outer (elevated) and inner (attracted to the surface) nanomesh sites is very different as a result of different chemical bonding to the substrate (weak and strong, respectively).