A low-energy electron microscopy and x-ray photo-emission electron microscopy study of Li intercalated into graphene on SiC(0001)
2010 (English)In: NEW JOURNAL OF PHYSICS, ISSN 1367-2630, Vol. 12, no 125015Article in journal (Refereed) Published
The effects induced by the deposition of Li on 1 and 0 ML graphene grown on SiC(0001) and after subsequent heating were investigated using low-energy electron microscopy (LEEM) and x-ray photo-emission electron microscopy (XPEEM). For 1 ML samples, the collected photoelectron angular distribution patterns showed the presence of single pi-cones at the six equivalent K-points in the Brillouin zone before Li deposition but the presence of two pi-cones (pi-bands) after Li deposition and after heating to a few hundred degrees C. For 0 ML samples, no pi-band could be detected close to the Fermi level before deposition, but distinct pi-cones at the K-points were clearly resolved after Li deposition and after heating. Thus Li intercalation was revealed in both cases, transforming the carbon buffer layer (0 ML) to graphene. On 1 ML samples, but not on 0 ML, a (root 3 x root 3) R30 degrees diffraction pattern was observed immediately after Li deposition. This pattern vanished upon heating and then wrinkles/cracks appeared on the surface. Intercalation of Li was thus found to deteriorate the quality of the graphene layer, especially for 1 ML samples. These wrinkles/cracks did not disappear even after heating at temperatures andgt;= 500 degrees C, when no Li atoms remained on the substrate.
Place, publisher, year, edition, pages
Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft , 2010. Vol. 12, no 125015
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-64573DOI: 10.1088/1367-2630/12/12/125015ISI: 000285585900012OAI: oai:DiVA.org:liu-64573DiVA: diva2:392812