Single-domain h-BN on Pt(110): Electronic structure, correlation, and bonding

Abstract

Extended single-domain growth of h-BN is observed on Pt(110), if the precursor molecules are deposited at sufficiently high temperatures. We examined the electronic structure of the h-BN/Pt(110) system by angle-resolved photoemission (ARPES), work-function measurements, and density-functional theory (DFT) calculations. van der Waals forces dominate the h-BN/Pt(110) interaction by far, although DFT analysis of the local density of states reveals the existence of a local covalent interaction of some N atoms with Pt surface atoms. The local bonding contributions cause the appearance of a (1×n) missing-row reconstruction (n=5 or 6) of the Pt (110) surface, if the system reverts to room temperature after h-BN adlayer formation at 1120 K. This unique phenomenon of the template adapting to the adlayer structure mitigates differences in the thermal-expansion coefficient upon cooling. The h-BN πbands hybridize with Pt d bands. Nevertheless, the dispersion of πand σ bands as measured by ARPES is overall well represented by the free-standing monolayer band structure except for the appearance of replica bands induced by the Moiré structure. A comparison between the experimentally measured πbands and the band structure obtained from DFT slab calculations suggest the existence of significant correlation effects in photoemission from h-BN/Pt(110). The locally varying distribution of N-Pt hybrid states straddling the Fermi level indicates a corresponding spatial variation of the chemical reactivity.