Reactive intercalation and oxidation at the buried graphene-germanium interface
Philipp Braeuninger-Weimer,
Oliver Burton,
Robert S. Weatherup,
Ruizhi Wang,
Pavel Dudin,
Barry Brennan,
Andrew J. Pollard,
Bernhard C. Bayer,
Vlad P. Veigang-Radulescu,
Jannik C. Meyer,
Billy J. Murdoch,
Peter J. Cumpson,
Stephan Hofmann
Affiliations
Philipp Braeuninger-Weimer
Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
Oliver Burton
Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
Robert S. Weatherup
The University of Manchester at Harwell, Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
Ruizhi Wang
Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
Pavel Dudin
Diamond Light Source, Didcot OX11 0DE, United Kingdom
Barry Brennan
National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, United Kingdom
Andrew J. Pollard
National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, United Kingdom
Bernhard C. Bayer
Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
Vlad P. Veigang-Radulescu
Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
Jannik C. Meyer
Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
Billy J. Murdoch
National EPSRC XPS Users’ Service (NEXUS), School of Mechanical and Systems Engineering, Newcastle University, Newcastle Upon Tyne NE1 7RU, United Kingdom
Peter J. Cumpson
National EPSRC XPS Users’ Service (NEXUS), School of Mechanical and Systems Engineering, Newcastle University, Newcastle Upon Tyne NE1 7RU, United Kingdom
Stephan Hofmann
Department of Engineering, University of Cambridge, Cambridge CB3 0FA, United Kingdom
We explore a number of different electrochemical, wet chemical, and gas phase approaches to study intercalation and oxidation at the buried graphene-Ge interface. While the previous literature focused on the passivation of the Ge surface by chemical vapor deposited graphene, we show that particularly via electrochemical intercalation in a 0.25 N solution of anhydrous sodium acetate in glacial acetic acid, this passivation can be overcome to grow GeO2 under graphene. Angle resolved photoemission spectroscopy, Raman spectroscopy, He ion microscopy, and time-of-flight secondary ion mass spectrometry show that the monolayer graphene remains undamaged and its intrinsic strain is released by the interface oxidation. Graphene acts as a protection layer for the as-grown Ge oxide, and we discuss how these insights can be utilized for new processing approaches.
