Silicon Carbide Stacking-Order-Induced Doping Variation in Epitaxial Graphene

authored by
Davood Momeni Pakdehi, Philip Schädlich, Thi Thuy Nhung Nguyen, Alexei A. Zakharov, Stefan Wundrack, Emad Najafidehaghani, Florian Speck, Klaus Pierz, Thomas Seyller, Christoph Tegenkamp, Hans Werner Schumacher
Abstract

Generally, it is supposed that the Fermi level in epitaxial graphene is controlled by two effects: p-type polarization doping induced by the bulk of the hexagonal silicon carbide (SiC)(0001) substrate and overcompensation by donor-like states related to the buffer layer. The presented work is evidence that this effect is also related to the specific underlying SiC terrace. Here a periodic sequence of non-identical SiC terraces is fabricated, which are unambiguously attributed to specific SiC surface terminations. A clear correlation between the SiC termination and the electronic graphene properties is experimentally observed and confirmed by various complementary surface-sensitive methods. This correlation is attributed to a proximity effect of the SiC termination-dependent polarization doping on the overlying graphene layer. These findings open a new approach for a nano-scale doping-engineering by the self-patterning of epitaxial graphene and other 2D layers on dielectric polar substrates.

External Organisation(s)
National Metrology Institute of Germany (PTB)
Chemnitz University of Technology (CUT)
MAX-lab
Type
Article
Journal
Advanced functional materials
Volume
30
ISSN
1616-301X
Publication date
04.11.2020
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Chemistry(all), Materials Science(all), Condensed Matter Physics
Electronic version(s)
https://doi.org/10.1002/adfm.202004695 (Access: Open)