Articulo
Experimental and theoretical investigation of the electronic structure of Cu2O and CuO thin films on Cu(110) using x-ray photoelectron and absorption spectroscopy
Autor
Jiang, Peng
Prendergast, David
Borondics, Ferenc
Porsgaard, Soeren
Giovanetti, Lisandro José
Pach, Elzbieta
Newberg, John
Bluhm, Hendrik
Besenbacher, Flemming
Salmeron, Miquel
Institución
Resumen
The electronic structure of Cu2O and CuO thin films grown on Cu(110) was characterized by X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The various oxidation states, Cu0, Cu+, and Cu2+, were unambiguously identified and characterized from their XPS and XAS spectra. We show that a clean and stoichiometric surface of CuO requires special environmental conditions to prevent loss of oxygen and contamination by background water. First-principles density functional theory XAS simulations of the oxygen K edge provide understanding of the core to valence transitions in Cu+ and Cu 2+. A novel method to reference x-ray absorption energies based on the energies of isolated atoms is presented. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas