A1 Refereed original research article in a scientific journal
Photoemission and density functional theory study of Ge(100): Clean surface and Yb-induced (2x4) reconstruction
Authors: Kuzmin M, Punkkinen MPJ, Laukkanen P, Perala RE, Lang JJK, Dahl J, Adell J, Kokko K
Publisher: Elsevier
Publication year: 2013
Journal: Surface Science
Journal name in source: SURFACE SCIENCE
Journal acronym: SURF SCI
Volume: 615
First page : 88
Last page: 96
Number of pages: 9
ISSN: 0039-6028
DOI: https://doi.org/10.1016/j.susc.2013.04.010(external)
Abstract
Clean and metal-adsorbed (100) surfaces of group-IV semiconductors, such as Si and Ge, often exhibit electronically and structurally similar reconstructions. However, the fundamental bulk properties of group-IV materials can have an impact on particular features of such systems, which are related, e.g., to final-state relaxation in photoemission and thus determine their spectral line shape. Here we have studied Yb/Ge(100)(2 x 4) reconstruction as well as clean Ge(100) surface by high-resolution photoelectron spectroscopy and ab initio calculations. An atomic geometry of both surfaces is thoroughly investigated. A detailed analysis of Ge 3d core-level photoemission, atomic origins of surface-shifted components, and final-state screening effects is presented. In particular, it is demonstrated that the core-hole screening plays an essential role in Ge 3d measurements, and that its amount in the complete screening model correlates well with the core-level binding energy of respective Ge atoms in the initial state. The results are discussed in the proper context of related reconstructions on Si(100). (C) 2013 Elsevier B.V. All rights reserved.
Clean and metal-adsorbed (100) surfaces of group-IV semiconductors, such as Si and Ge, often exhibit electronically and structurally similar reconstructions. However, the fundamental bulk properties of group-IV materials can have an impact on particular features of such systems, which are related, e.g., to final-state relaxation in photoemission and thus determine their spectral line shape. Here we have studied Yb/Ge(100)(2 x 4) reconstruction as well as clean Ge(100) surface by high-resolution photoelectron spectroscopy and ab initio calculations. An atomic geometry of both surfaces is thoroughly investigated. A detailed analysis of Ge 3d core-level photoemission, atomic origins of surface-shifted components, and final-state screening effects is presented. In particular, it is demonstrated that the core-hole screening plays an essential role in Ge 3d measurements, and that its amount in the complete screening model correlates well with the core-level binding energy of respective Ge atoms in the initial state. The results are discussed in the proper context of related reconstructions on Si(100). (C) 2013 Elsevier B.V. All rights reserved.
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