Buffer layer free large area bi-layer graphene on SiC(0001)
2010 (English)In: SURFACE SCIENCE, ISSN 0039-6028, Vol. 604, no 2, L4-L7 p.Article in journal (Refereed) Published
The influence of hydrogen exposures on monolayer graphene grown on the silicon terminated SiC(0 0 0 1) surface is investigated using photoelectron spectroscopy (PES), low-energy electron microscopy (LEEM) and micro low-energy electron diffraction (mu-LEED). Exposures to ionized hydrogen are shown to have a pronounced effect on the carbon buffer (interface) layer. Exposures to atomic hydrogen are shown to actually convert/transform the monolayer graphene plus carbon buffer layer to bi-layer graphene, i.e. to produce carbon buffer layer free bi-layer graphene on SiC(0 0 0 1). This process is shown to be reversible, so the initial monolayer graphene plus carbon buffer layer situation is recreated after heating to a temperature of about 950 degrees C. A tentative model of hydrogen intercalation is suggested to explain this single to bi-layer graphene transformation mechanism. Our findings are of relevance and importance for various potential applications based on graphene-SiC structures and hydrogen storage.
Place, publisher, year, edition, pages
2010. Vol. 604, no 2, L4-L7 p.
Graphene, Bi-layer, Epitaxial, Silicon carbide, LEEM, PES, Hydrogenation, LEED
National CategoryEngineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-54251DOI: 10.1016/j.susc.2009.11.011ISI: 000274591000002OAI: oai:DiVA.org:liu-54251DiVA: diva2:302300