Oxygen intercalation below epitaxial graphene

Oxygen intercalation below an extended layer of epitaxial graphene on Ir(111) is demonstrated using  real-time High-Resolution Photoemission Spectroscopy (HR-XPS). The resulting “lifted” graphene is decoupled from the Ir substrate and slightly p-doped as indicated by Angular Resolved Photoemission Spectroscopy (ARPES).


R. Larciprete et al., ACS Nano 6, 9551 (2012).

Oxygen intercalation below a complete layer of graphene can be achieved by proper combination of sample temperature and oxygen partial pressure. Oxygen adsorption below graphene proceeds as on clean Ir(111), resulting only in a slightly higher coverage.
Upon intercalation, the graphene layer presents a C 1s core level shifted to lower binding energy because of the charge transfer from the oxygen-covered metal surface. In the ARPES data the characteristic spectral signatures of the graphene-iridium interaction disappear and the valence band map shows the spectrum of a hole-doped, quasi free-standing graphene layer.

Moreover, temperature programmed photoemission (TP-XPS) experiments demonstrate that the system is stable up to 600 K.

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Oxygen Switching of the Epitaxial Graphene-Metal Interaction;
Rosanna Larciprete, Søren Ulstrup, Paolo Lacovig, Matteo Dalmiglio,  Marco Bianchi, Federico Mazzola, Liv Hornekær, Fabrizio Orlando, Alessandro Baraldi, Philip Hofmann, and  Silvano Lizzit;
ACS Nano 6, 9551 (2012).
Last Updated on Tuesday, 06 September 2016 15:47