PHOTOELECTRON-SPECTROSCOPY OF NICKEL ON ZINC-OXIDE IN THE MONOLAYER AND SUBMONOLAYER RANGE

Nickel films of thicknesses between 0.05 and 5 monolayers were deposited by evaporation onto the polar ZnO(0001)Zn and ZnO(0001)O surfaces. The character and thickness of the Ni films were determined by Auger electron spectroscopy. The work function, the bending of the substrate bands and the emission from the Ni 3d states were studied by UV photoelectron spectroscopy. After deposition of about 2 monolayers of Ni the O face showed an upward band bending whereas the Zn face showed hardly any at all. After reaching a film thickness of about one monolayer the emission from the Ni 3d states becomes similar to that from the 3d band of bulk Ni. For a film thickness below 0.2 of a monolayer the emission features at -4.3 eV and -6.0 eV were attributed to Ni atoms interacting with oxygen from the substrate and the features at -2.1 and -1.3 to Ni atoms and two-dimensional Ni clusters. © 1979.