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

    M3 - Article

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    JF - Journal of chemical physics

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