Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O2 molecules

R. Friedlein, B. Van Hao, Frank Bert Wiggers, Y. Yamada-Takamura, Alexeij Y. Kovalgin, Machiel Pieter de Jong

Research output: Contribution to journalArticleAcademicpeer-review

18 Citations (Scopus)

Abstract

As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O2 molecules, as well as the combination of both, with epitaxial silicene on thin ZrB2(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O2 gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O2 molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.
Original languageUndefined
Article number204705
Pages (from-to)204705:1-204705:4
Number of pages4
JournalJournal of chemical physics
Volume140
DOIs
Publication statusPublished - 27 May 2014

Keywords

  • EWI-24781
  • IR-91347
  • METIS-304110

Cite this

Friedlein, R. ; Van Hao, B. ; Wiggers, Frank Bert ; Yamada-Takamura, Y. ; Kovalgin, Alexeij Y. ; de Jong, Machiel Pieter. / Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O2 molecules. In: Journal of chemical physics. 2014 ; Vol. 140. pp. 204705:1-204705:4.
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abstract = "As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O2 molecules, as well as the combination of both, with epitaxial silicene on thin ZrB2(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O2 gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O2 molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.",
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Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O2 molecules. / Friedlein, R.; Van Hao, B.; Wiggers, Frank Bert; Yamada-Takamura, Y.; Kovalgin, Alexeij Y.; de Jong, Machiel Pieter.

In: Journal of chemical physics, Vol. 140, 204705, 27.05.2014, p. 204705:1-204705:4.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Interaction of epitaxial silicene with overlayers formed by exposure to Al atoms and O2 molecules

AU - Friedlein, R.

AU - Van Hao, B.

AU - Wiggers, Frank Bert

AU - Yamada-Takamura, Y.

AU - Kovalgin, Alexeij Y.

AU - de Jong, Machiel Pieter

N1 - eemcs-eprint-24781

PY - 2014/5/27

Y1 - 2014/5/27

N2 - As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O2 molecules, as well as the combination of both, with epitaxial silicene on thin ZrB2(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O2 gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O2 molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.

AB - As silicene is not chemically inert, the study and exploitation of its electronic properties outside of ultrahigh vacuum environments require the use of insulating capping layers. In order to understand if aluminum oxide might be a suitable encapsulation material, we used high-resolution synchrotron photoelectron spectroscopy to study the interactions of Al atoms and O2 molecules, as well as the combination of both, with epitaxial silicene on thin ZrB2(0001) films grown on Si(111). The deposition of Al atoms onto silicene, up to the coverage of about 0.4 Al per Si atoms, has little effect on the chemical state of the Si atoms. The silicene-terminated surface is also hardly affected by exposure to O2 gas, up to a dose of 4500 L. In contrast, when Al-covered silicene is exposed to the same dose, a large fraction of the Si atoms becomes oxidized. This is attributed to dissociative chemisorption of O2 molecules by Al atoms at the surface, producing reactive atomic oxygen species that cause the oxidation. It is concluded that aluminum oxide overlayers prepared in this fashion are not suitable for encapsulation since they do not prevent but actually enhance the degradation of silicene.

KW - EWI-24781

KW - IR-91347

KW - METIS-304110

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DO - 10.1063/1.4878375

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