XPS study on band alignment at Pt-O-terminated ZnO(000(1)over-bar) interface

The band alignment at the interface between Pt and O-terminated ZnO(000 (1) over bar) was investigated by depositing Pt films on ZnO using X-ray photoelectron spectroscopy and ultra violet photoelectron spectroscopy in an ultrahigh vacuum system. Angle-resolved X-ray photoelectron spectroscopy measurement showed the band was bent down by 0.06 eV at the ZnO(000 (1) over bar) surface. The binding energy of Zn 2p doublet shifted toward higher values by 0.37 eV when Pt was deposited on ZnO(000 (1) over bar). The work function of ZnO(000 (1) over bar) was 4.08 eV and the valence band maximum measured by UPS on the clean ZnO(000 (1) over bar) surface was 2.82 eV. As a result, the Schottky barrier height of Pt/ZnO(000 (1) over bar) was 0.72 eV in this experiment. Copyright (C) 2010 John Wiley & Sons, Ltd.