Author:
Grubišić-Čabo Antonija,Kotsakidis Jimmy C.,Yin Yuefeng,Tadich Anton,Haldon Matthew,Solari Sean,Riley John,Huwald Eric,Daniels Kevin M.,Myers-Ward Rachael L.,Edmonds Mark T.,Medhekar Nikhil V.,Gaskill D. Kurt,Fuhrer Michael S.
Abstract
We study quasi-freestanding bilayer graphene on silicon carbide intercalated by calcium. The intercalation, and subsequent changes to the system, were investigated by low-energy electron diffraction, angle-resolved photoemission spectroscopy (ARPES) and density-functional theory (DFT). Calcium is found to intercalate only at the graphene-SiC interface, completely displacing the hydrogen terminating SiC. As a consequence, the system becomes highly n-doped. Comparison to DFT calculations shows that the band dispersion, as determined by ARPES, deviates from the band structure expected for Bernal-stacked bilayer graphene. Instead, the electronic structure closely matches AA-stacked bilayer graphene on calcium-terminated SiC, indicating a spontaneous transition from AB- to AA-stacked bilayer graphene following calcium intercalation of the underlying graphene-SiC interface.
Funder
Australian Research Council
Subject
Electrical and Electronic Engineering,Computer Science Applications,Biomedical Engineering,Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials