Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 82: Graphene IV

O 82.4: Vortrag

Freitag, 26. März 2010, 12:00–12:15, H31

Low Temperature Epitaxial Graphene on SiC by Carbon Deposition — •Ameer Al-Temimy, Christian Riedl, and Ulrich Starke — Max Planck Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany

Epitaxial graphene displays unconventional electronic properties that make it an interesting material for carbon based nanolectronics. The epitaxial growth of graphene on silicon carbide (SiC) is a promising route to achieve large graphene samples. Conventionally, on SiC(0001) in an ultrahigh vacuum (UHV) system, monolayer graphene is prepared by annealing to about 1200 ^∘C. Using low energy electron diffraction (LEED) and angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) we demonstrate that monolayer graphene can also be grown at a lower temperature of about 950 ^∘C under simultaneous carbon deposition. As shown by atomic force microscopy (AFM) the approach of carbon deposition modifies the growth dynamics of graphene so that the initial surface morphology of the SiC crystal is preserved in contrast to the conventional method. On SiC(0001), LEED demonstrates that the carbon evaporation induced epitaxial graphene grows with a predominant lattice orientation of 0^∘ with respect to the substrate instead of 30^∘ as observed for the conventional UHV preparation. The new approach of carbon evaporation on SiC crystals opens up pathways in the investigation of SiC surface phase diagrams and for low temperature procedures in graphene growth.