J. Hass

Electronic Confinement and Coherence in Patterned Epitaxial Graphene

Ultrathin epitaxial graphite was grown on single-crystal silicon carbide by vacuum graphitization. The material can be patterned using standard nanolithography methods. The transport properties, which are closely related to those of carbon nanotubes, are dominated by the single epitaxial graphene layer at the silicon carbide interface and reveal the Dirac nature of the charge carriers. Patterned structures show quantum confinement of electrons and phase coherence lengths beyond 1 micrometer at 4 kelvin, with mobilities exceeding 2.5 square meters per volt-second. All-graphene electronically coherent devices and device architectures are envisaged.

The growth and morphology of epitaxial multilayer graphene

The electronic properties of epitaxial graphene grown on SiC have shown its potential as a viable candidate for post-CMOS electronics. However, progress in this field requires a detailed understanding of both the structure and growth of epitaxial graphene. To that end, this review will focus on the current state of epitaxial graphene research as it relates to the structure of graphene grown on SiC. We pay particular attention to the similarity and differences between graphene growth on the two polar faces, (0001) and , of hexagonal SiC. Growth techniques, subsequent morphology and the structure of the graphene/SiC interface and graphene stacking order are reviewed and discussed. Where possible the relationship between film morphology and electronic properties will also be reviewed.

Electronic Structure of Epitaxial Graphene Layers on SiC: Effect of the Substrate

A strong substrate-graphite bond is found in the first all-carbon layer by density functional theory calculations and x-ray diffraction for few graphene layers grown epitaxially on SiC. This first layer is devoid of graphene electronic properties and acts as a buffer layer. The graphene nature of the film is recovered by the second carbon layer grown on both the (0001) and (0001[over]) 4H-SiC surfaces. We also present evidence of a charge transfer that depends on the interface geometry. Hence the graphene is doped and a gap opens at the Dirac point after three Bernal stacked carbon layers are formed.

Highly ordered graphene for two dimensional electronics

With expanding interest in graphene-based electronics, it is crucial that high quality graphene films be grown. Sublimation of Si from the 4H-SiC(0001) (Si-terminated) surface in ultrahigh vacuum is a demonstrated method to produce epitaxial graphene sheets on a semiconductor. In this letter the authors show that graphene grown from the SiC(0001¯) (C-terminated) surface are of higher quality than those previously grown on SiC(0001). Graphene grown on the C face can have structural domain sizes more than three times larger than those grown on the Si face while at the same time reducing SiC substrate disorder from sublimation by an order of magnitude.

Structural properties of the multilayer graphene/4H-SiC(0001) system as determined by surface x-ray diffraction

We present a structural analysis of the multilayer graphene/

Interface structure of epitaxial graphene grown on 4H-SiC(0001)

4H\mathrm{Si}\mathrm{C}(000\overline{1})

Dirac Particles in Epitaxial Graphene Films Grown on SiC

system using surface x-ray reflectivity. We show that graphene films grown on the C-terminated

Why Multilayer Graphene on 4H-SiC(000-1) Behaves Like a Single Sheet of Graphene

(000\overline{1})

TOPICAL REVIEW: The growth and morphology of epitaxial multilayer graphene

surface have a graphene-substrate bond length that is very short

Rotational stacking and its electronic effects on graphene films grown on 4H-SiC

(1.62\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}})