Electronic states and growth modes of Zn atoms deposited on Cu(111) studied by XPS, UPS and DFT

Electronic states and growth modes of the Zn-deposited Cu(111) surface at 300K were quantitatively studied using core-level and valence photoelectron spectroscopies. Both Cu 2p and Zn 2p core-levels shifted to higher binding energy with increasing the amount of deposited Zn up to multilayer. The origin of the core-level shift of Cu 2p was further investigated by density functional theory calculations; the shift of the Cu 2p peak results from the change in the effective electrostatic potential (initial state effect) caused by the formation of Zn-Cu surface alloy, and the increase of coordination numbers of surface Cu atoms by Zn overlayer. The observed valence photoelectron spectra show the formation of the two atomic-layer Zn-Cu alloy up to the Zn coverage of 1ML, followed by the formation of three-dimensional Zn islands on the alloyed surface at 300K. [Display omitted] •Cu and Zn core-levels shift to higher binding energy with increasing Zn coverage.•DFT calculations indicate that Cu 2p is shifted due to the initial state effects.•Alloying continues up to θZn=1ML, followed by three-dimensional Zn island growth.