Electronic and chemical properties of In and Sb adsorbed on Ge(100) studied by synchrotron photoemission

Journal Article · Thu Feb 15 04:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.3004· OSTI ID:6965743

Rich, D H; Miller, T; Chiang, T ^[1]

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1. Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (US) Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 South Goodwin Avenue, Urbana, Illinois 61801

The initial stages of interface formation for In and Sb, each separately adsorbed on the Ge(100)-(2{times}1) surface, have been investigated for various submonolayer coverages with use of synchrotron-photoemission and high-energy electron-diffraction techniques. By examining the evolution of the substrate and adsorbate core-level line shapes during the adsorbate growth it is possible to deduce chemical and structural information. The dimer-related surface-shifted component of the Ge 3{ital d} core level is found to gradually convert into a component possessing a binding energy indistinguishable from the bulk component for increasing Sb coverages. For submonolayer In depositions, this surface-shifted component results in a chemically shifted interface component which is distinguishable from the emission from bulk atoms and unreacted Ge dimers. The resulting chemical shifts are consistent with expectations based on electronegativity arguments. For both In and Sb, the adsorbate-to-substrate bonding coordination number is obtained for various submonolayer coverages. The homogeneity of the adsorbate bonding is evaluated by examining the width of the In and Sb 4{ital d} core-level line shapes. The Fermi-level position relative to the gap for various In and Sb coverages and the Schottky-barrier heights are obtained. Photoemission from the valence bands shows a modification in the dimer-derived surface states upon In and Sb adsorption; the surfaces show little density of states at the Fermi level for coverages below 1 monolayer. Structural models for the In/Ge(100)-(2{times}2) and Sb/Ge(100)-(2{times}1) surfaces which correlate with the data are discussed.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6965743
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:5; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ADSORPTION
ANTIMONY
BREMSSTRAHLUNG
CHEMICAL PROPERTIES
COHERENT SCATTERING
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY LEVELS
FERMI LEVEL
GERMANIUM
INDIUM
INTERFACES
METALS
PHOTOELECTRON SPECTROSCOPY
RADIATIONS
SCATTERING
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
STRUCTURAL MODELS
SURFACE PROPERTIES
SYNCHROTRON RADIATION
SYNTHESIS