Epitaxial graphene on 3C-SiC(111) pseudosubstrate: Structural and electronic properties

Abstract

International audienceStructural and electronic properties of epitaxial graphene on 3C-SiC(111) pseudosubstrate epilayers on silicon was investigated in detail by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), scanning transmission electron microscopy (STEM), and synchrotron angle-resolved photoemission spectroscopy (ARPES). The graphitization process has been observed by distinct features in the atomically resolved STM images and abrupt interface with the number of stacked-graphene layer has been revealed in STEM image. Two different types of carbon atom networks, honeycomb and one sublattice, were atomically resolved by STM. Electronic properties and band structures of the epitaxial graphene are examined with angle-resolved photoemission spectroscopy, showing linear band dispersion K point of the Brillouin zone, with Dirac point about 500 meV below the Fermi level (E-F). These findings are of relevance for various potential applications based on graphene-SiC/Si(111) structures

Effect of oxygen adsorption on the local properties of epitaxial graphene on SiC (0001)

“…The LEED image of the clean and unexposed surface ( Fig. 1(c)) proves the good crystalline quality of the graphene layer, implying that only few defects are present on the surface [12]. Moreover and as it will discussed hereafter, the ARPES measurements evidence a clear Dirac cone at the K point of the Brillouin zone after oxidation, which is also a fingerprint of the high graphene layer quality.…”

“…After polishing, the sample was exposed to hydrogen etching at 1600°C in order to remove polishing damages. The sample was further annealed at 1300-1400°C to grow the graphene layers under argon and silicon fluxes, as it favors the formation of large and homogeneous domains [12,13]. During the graphitization process, the Ar partial pressure was kept below P = 2×10 −5 Torr.…”

Large-area microfocal spectroscopic ellipsometry mapping of thickness and electronic properties of epitaxial graphene on Si- and C-face of 3C-SiC(111)

“…Very few studies on graphene growth on the Si-face of 3C-SiC(111) on Si have been performed, and terrace growth of EG with domain sizes of few micrometers and limited homogeneity was reported. 8,9 3C-SiC offers a number of advantages over piezoelectric polytypes of SiC because of its isotropic and unpolarized growth surfaces and the reported performance improvement of SiC-based electronic devices.…”

Laterally Inhomogeneous Au Intercalation in Epitaxial Graphene on SiC(0 0 0 1): A Multimethod Electron Microscopy Study

“…In order to investigate the effect of Au deposition on the electronic properties, we have performed local ARPES experiments (µARPES). [9,17,24] and is attributed to doping from the buffer layer [6,7]. On the 2D µARPES map, recorded after Au deposition (Figure 4b), the energy difference between the Fermi level and the Dirac point is still 0.40 ± 0.02 eV.…”

“…It is now well established that, in this system, the interaction between the graphene and its supporting substrate (SiC) can affect considerably the electronic properties of graphene. Indeed, it is known that the first carbon layer onto a SiC substrate is covalently bonded to the Si atoms of the substrate, and this "buffer layer" does not display graphitic electronic properties [5][6][7][8]. Moreover, the remaining unsaturated Si dangling bonds, at the buffer layer/SiC interface, induce a high intrinsic n-doping in graphene, which degrades the carrier mobility.…”