Electronic states of monolayer hexagonal boron nitride formed on the metal surfaces

By using angle-resolved ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy and electron energy loss spectroscopy (EELS), we have investigated the electronic properties of monolayer films of hexagonal boron nitride (h-BN) formed on Ni(111), Pd(111) and Pt(111). Because of the weakness of the interfacial bonding, the electronic structure of monolayer BN is almost independent of the substrate and the energy bands and core-levels in the BN film are aligned to the vacuum level, not to the Fermi level. In accordance with these results, the EELS spectra observed for the BN-metal systems change from one substrate to the other depending on the work function.