Rb and Cs deposition on epitaxial graphene grown on 6H-SiC(0001)
2011 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 605, no 21-22, 1918-1922 p.Article in journal (Refereed) Published
Epitaxial graphene grown on the silicon-terminated SiC(0001) is doped by alkali metals deposited on the surface. The synchrotron radiation based photoelectron spectroscopy results presented reveal that Rb and Cs deposited on monolayer graphene samples, grown on the silicon-terminated SiC(0001), gives rise to n-type doping, i.e. electron transfer from the metal to the graphene layer. The Dirac point of the single pi-cone is found to shift downwards away from the Fermi level by ca. 1.0 eV after alkali metal depositions. The adsorbed Rb and Cs atoms do initially disrupt the bonds in the graphene layer but after heating the bonds appear to be recreated when the alkali metal coverage start to decrease due to thermal desorption. None of these two alkali metals do intercalate into the graphene and buffer layer after depositing at room temperature or after heating. This is contrary to the case of Li where intercalation occurred directly after deposition.
Place, publisher, year, edition, pages
Elsevier , 2011. Vol. 605, no 21-22, 1918-1922 p.
Epitaxial graphene, Metal deposition, Rubidium, Cesium, Silicon carbide, Core-level photoelectron spectroscopy, ARPES
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-71374DOI: 10.1016/j.susc.2011.07.007ISI: 000295244700010OAI: oai:DiVA.org:liu-71374DiVA: diva2:448073
Funding Agencies|Swedish National Energy Administration||2011-10-142011-10-142011-12-29