Interfacial quantum well states of Xe and Kr adsorbed on Ag(111)

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.472209· OSTI ID:286921

McNeill, J D; Lingle, Jr, R L; Jordan, R E; Padowitz, D F; Harris, C B ^[1]

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1. Department of Chemistry, University of California, Berkeley, California 94720 (United States)

The energies and dispersions of the image states and quantum well electronic states in layers of Xe and Kr on a Ag(111) substrate were determined by angle-resolved two-photon photoemission (ARTPPE). For Xe, we measured binding energies of unoccupied electronic states for 1{endash}9 layers and their parallel dispersion out to 4 layers. We measured the binding energies for a monolayer of Kr and dispersions for one and two layers. The {ital n}=2 and {ital n}=3 image states of the bare metal evolve into quantum well states of the layer (states of the Xe conduction band discretized by the boundary conditions of a 2-D slab) at higher Xe thicknesses, where the {ital n}=2,3 states exhibit both a perpendicular and parallel dispersion similar to that of the bulk Xe conduction band. The {ital n}=1 state appears to evolve with coverage as an image state screened by the Xe layer, with appreciable electron density in the vacuum. A continuum dielectric model (modified image state picture) reproduces the gross trends in the data, while an explicit quantum well analysis is used to extract the bulk Xe conduction band dispersion. A simple model which takes into account the band structures of the substrate and the overlayer, as well as the image potential, gives good agreement with the binding energy data. The combination of high energy and momentum resolution along both the surface parallel and surface normal yields very precise measurements of the bulk Xe conduction band as well as information about the behavior of conduction band electrons at interfaces. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 286921
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 9 Vol. 105; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ADSORPTION
BAND STRUCTURE
BINDING ENERGY
BOUNDARY CONDITIONS
ELECTRON DENSITY
ELECTRONIC STRUCTURE
INTERFACE PHENOMENA
KRYPTON
PHOTOEMISSION
QUANTUM WELLS
SILVER
TWO-PHOTON SPECTRA
XENON