Surfactant-Mediated Epitaxial Growth of Single-Layer Graphene in an Unconventional Orientation on SiC

• Published in: Physical review letters 2020-09, Vol.125 (10), p.1-106102, Article 106102
• Main Authors: Bocquet, F. C., Lin, Y.-R., Franke, M., Samiseresht, N., Parhizkar, S., Soubatch, S., Lee, T.-L., Kumpf, C., Tautz, F. S.
• Format: Article
• Language: English
• Subjects: Bilayers; Epitaxial growth; Graphene; Homogeneity; Low energy electron diffraction; Monolayers; Orientation; Photoelectrons; Quality assessment; Standing waves; Substrates; Surfactants; Wave diffraction
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.125.106102

We report the use of a surfactant molecule during the epitaxy of graphene on SiC(0001) that leads to the growth in an unconventional orientation, namely R0° rotation with respect to the SiC lattice. It yields a very high-quality single-layer graphene with a uniform orientation with respect to the substrate, on the wafer scale. We find an increased quality and homogeneity compared to the approach based on the use of a preoriented template to induce the unconventional orientation. Using spot profile analysis low-energy electron diffraction, angle-resolved photoelectron spectroscopy, and the normal incidence x-ray standing wave technique, we assess the crystalline quality and coverage of the graphene layer. Combined with the presence of a covalently bound graphene layer in the conventional orientation underneath, our surfactant-mediated growth offers an ideal platform to prepare epitaxial twisted bilayer graphene via intercalation.