Magnesium-intercalated graphene on SiC: highly n-doped air-stable bilayer graphene at extreme displacement fields
| Autor: | Mark T. Edmonds, Jimmy C. Kotsakidis, Kevin M. Daniels, Anton Tadich, D. Kurt Gaskill, Michael S. Fuhrer, J.D. Riley, Iolanda Di Bernardo, Sean Solari, Antonija Grubišić-Čabo, Yuefeng Yin, Rachael L. Myers-Ward, Matthew Haldon, Nikhil V. Medhekar, E. Huwald |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Photoemission spectroscopy Band gap FOS: Physical sciences General Physics and Astronomy Angle-resolved photoemission spectroscopy 02 engineering and technology Electronic structure 010402 general chemistry 01 natural sciences law.invention chemistry.chemical_compound law Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Silicon carbide Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Graphene Doping Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films chemistry 0210 nano-technology Bilayer graphene |
| Popis: | We use angle-resolved photoemission spectroscopy to investigate the electronic structure of bilayer graphene at high n-doping and extreme displacement fields, created by intercalating epitaxial monolayer graphene on silicon carbide with magnesium to form quasi-freestanding bilayer graphene on magnesium-terminated silicon carbide. Angle-resolved photoemission spectroscopy reveals that upon magnesium intercalation, the single massless Dirac band of epitaxial monolayer graphene is transformed into the characteristic massive double-band Dirac spectrum of quasi-freestanding bilayer graphene. Analysis of the spectrum using a simple tight binding model indicates that magnesium intercalation results in an n-type doping of 2.1 $\times$ 10$^{14}$ cm$^{-2}$, creates an extremely high displacement field of 2.6 V/nm, opening a considerable gap of 0.36 eV at the Dirac point. This is further confirmed by density-functional theory calculations for quasi-freestanding bilayer graphene on magnesium-terminated silicon carbide, which show a similar doping level, displacement field and bandgap. Finally, magnesium-intercalated samples are surprisingly robust to ambient conditions; no significant changes in the electronic structure are observed after 30 minutes exposure in air. 46 pages including supporting information, 4 figures in the main paper and 9 figures in the supporting information |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|