Berlin 2024 – scientific programme
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O: Fachverband Oberflächenphysik
O 94: Focus Session: Proximity Effects in Epitaxial Graphene I
O 94.2: Talk
Thursday, March 21, 2024, 15:30–15:45, MA 141
Investigating intercalated Lead layers underneath epitaxial graphene — •Philip Schädlich1,2, Franziska Schölzel1, Peter Richter1,2, and Thomas Seyller1,2 — 1Technische Universität Chemnitz, Institut für Physik, 09126 Chemnitz — 2Center for Materials, Architectures and Integration of Nanomembranes (MAIN), 09126 Chemnitz
Intercalation is a promising approach for tailoring the electronic structure of epitaxial graphene on SiC. Beyond that, it enables the formation of otherwise unstable two-dimensional (2D) phases of elements and opens a route to investigate the interplay between the two 2D materials and the substrate [1,2].
We have studied in detail the Pb intercalation process itself, as well as the structure and electronic properties of the 2D Pb layer by means of low-energy electron microscopy and photoelectron spectroscopy (PES). Probing the electronic structure using angle-resolved PES reveals a strict (1×1) periodicity of the intercalated Pb with respect to the substrate. The quasi-freestanding graphene turns out to be effectively screened from the doping influence of the substrate leading to charge-neutrality. In fact, the 2D Pb layer is compensating the spontaneous polarization of the substrate. Our results experimentally quantify the interaction between the 2D Pb layer, the substrate and the graphene layer and demonstrate a first step towards controlling the diversity of 2D Pb phases.
[1] C. Ghosal, Phys. Rev. Lett. 129, 116802 (2022), [2] P. Rosenzweig, Phys. Rev. B 101, 201407(R) (2020)
Keywords: Epitaxial Graphene; Intercalation; Proximity Coupling; Spontaneous Polarization; Doping