Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 68: Semiconductor substrates: Epitaxy and growth
O 68.5: Vortrag
Donnerstag, 25. März 2010, 11:30–11:45, H42
Characterization of copper-metallized ZnO and brass surfaces with STM, SEM and XPS — •Vadim Schott1, Zhinong Wang1, David Silber1, Franziska Traeger1, Alexander Birkner1, Martin Kroll2, Ulrich Köhler2, and Christof Wöll1,3 — 1Chair of physical chemistry I, Ruhr-Universität Bochum, Germany — 2Experimental Physics IV, Surface Science Group, Ruhr-Universität Bochum, Germany — 3Institute of functional interfaces, Karlsruhe Institute of Technology, Germany
The metal-substrate interaction is of particular importance for a better understanding of the methanol synthesis process using Cu/ZnO containing catalysts. Scanning tunneling microscopy (STM) and scanning electron microscopy (SEM) was used to investigate the topography of the copper-metallized ZnO and brass surfaces. Addionally x-ray photoelectron spectroscopy (XPS) reveals information about the chemical composition and the oxidation states of surface atoms. Our ultrahigh vacuum (UHV) apparatus allows STM-, SEM-Imaging and XPS measurements at the same sample position. The initial preparation of the ZnO single crystals is done by cycles of Ar-sputtering (E=800eV) and annealing up to 700°C. Then Cu is deposited by molecular beam epitaxy (MBE). In this work we focus on the growth of Cu on the different ZnO surfaces, diffusion of Cu into ZnO and the feasibility of brass formation. The next step of our research is the characterization of brass single crystals. After initial preparation of the crystals and additional oxidation ZnO layers are growing on the surface. The orientation of this ZnO layer was determined using pyridine as a probe molecule.