Induced surface states of the ultrathin Ва/3$C$-SiC(111) interface

The electronic properties of the Ba/3$C$-SiC(111) nanointerface are for the first time studied by photoelectron spectroscopy with the use of synchrotron radiation in the energy range 80–450 eV. The experiments are performed in situ in ultrahigh vacuum for ultrathin Ba coatings on 3$C$-SiC(111) samples grown by a new method of substituting substrate atoms. It is found that the adsorption of Ba brings about the appearance of induced surface states with the binding energies 1.9, 6.2, and 7.5 eV. Evolution of the surface states and the spectra of the Si 2$p$ and C 1$s$ core levels shows that the Ba/3$C$-SiC(111) interface is formed due to charge transfer from Ba adatoms to surface Si atoms and underlying C atoms.