Structural and electronic properties of Li-intercalated graphene on SiC(0001)

Abstract

We investigate the structural and electronic properties of Li-intercalated monolayer graphene on SiC(0001) using combined angle-resolved photoemission spectroscopy and first-principles density functional theory. Li intercalates at room temperature both at the interface between the buffer layer and SiC and between the two carbon layers. The graphene is strongly n-doped due to charge transfer from the Li atoms and two π bands are visible at theK point. After heating the sample to 300• C, these π bands become sharp and have a distinctly different dispersion to that of Bernal-stacked bilayer graphene. We suggest that the Li atoms intercalate between the two carbon layers with an ordered structure, similar to that of bulk LiC 6 . An AA stacking of these two layers becomes energetically favourable. The π bands around theK point closely resemble the calculated band structure of a C 6 LiC 6 system, where the intercalated Li atoms impose a superpotential on the graphene electronic structure that opens gaps at the Dirac points of the two π cones.

Massive and massless charge carriers in an epitaxially strained alkali metal quantum well on graphene

“…Regarding the structure of bilayer graphene, we observe, that after the intercalation, graphene changes from AB (Bernal) to AA stacking for all investigated structures. This is consistent with previous findings on Li-intercalated graphene 70 .…”

Changes in work function due to NO2 adsorption on monolayer and bilayer epitaxial graphene on SiC(0001)

“…The experimentally determined (6 √ 3 × 6 √ 3)R30 • carbon buffer layer (also known as zero layer graphene or ZLG) [28][29][30][31] is modeled using a simplified √ 3 × √ 3R30 • cell, which has previously been shown to adequately describe the interaction between the SiC substrate and subsequent graphene layers [32][33][34]. A vacuum layer of at least 17Å is included in the direction normal to the surface to electronically decouple neighboring slabs and the dipole correction is applied [35,36].…”

Lithium Intercalation in Bilayer Graphene Devices

“…We also include schematic side views of the topmost atomic layers of the studied sample. Carey et al 140 rst sublimated Si from a 4H-SiC(0001) wafer, such that two graphene layers remain on its surface. As the lower one, the so-called buer layer, is partially bound to the SiC substrate, only the upper one shows electronic states near the Fermi energy F = 0 in Fig.…”