Graphene has paved the way to a widespread interest in two dimensional materials. Due to its peculiar electronic, mechanical, and electron-transport properties it is regarded as a promising material for nanoelectronic and spintronic applications. Many efforts have thus been made to find proper substrates and efficient processes for high quality graphene growth, and SiC has been found to be one of the leading solutions. However, the absence of a tunable band gap in graphene is a crucial barrier for nanoelectronics applications. Moreover, the strong covalent interactions with the SiC in graphene/SiC heterostructures results in a high electron doping in graphene, which affects the charge carrier mobility [1]. Finding an efficient way to open a band gap and decouple graphene from the substrates is thus essential . A solution to overcome these obstacles, which has attracted much interest in recent years, is the intercalation of atomic species into the graphene/substrate interface. In fact, two key factors in the opening and tuning a band gap in graphene are the symmetry breaking of the sublattice and the presence of strong spin-orbit (SO) interaction. Intercalated metals have become promising to engineer a large band gap in graphene via spin-orbit coupling. Several species have been found to be able to intercalate in the graphene layer like H, Au, Pt, Li, Na, F, Mn, Si, Ge. Among them, intercalation of heavy atoms like Pb with large SO coupling was used to modify the energy spectra and density of states of graphene in order to make it equivalent to the energy levels of a 2D electron gas in a constant magnetic field [2][3]. It has been experimentally observed that twisted Plumbene is able to open a gap of 30 meV at the Fermi energy [4]. Moreover, it has been found that intercalating atoms under epitaxial graphene can efficiently decouple it from the substrate. The aim of this work is to investigate, via DFT calculations, the intercalation of a 2D plumbene layer in graphene on a SiC substrate. Calculation of DOS and band structure projection onto atomic states highlight the effect of Pb intercalation in altering the dispersion of the states near the Dirac cones due to energy levels hybridization. Analysis of the vacuum level, work function as well as investigation of charge transfer in the designed Van der Waals heterostructure, before and after intercalation, are included in this study. Starting from the choice of a proper coincidence lattice, calculations also reveal, after the intercalation, the formation of a disordered Pb monolayer covalently bonded to the SiC substrate. [1] C. Riedl et al 2010 J. Phys. D: Appl. Phys. 43 374009[2] A. Yurtsever et al. Small 12.29 (2016): 3956-3966.[3] S. Chen, et al. Physical Review Materials 4.12 (2020): 124005.[4] C. Ghosal, et al. Physical Review Letters 129.11 (2022): 116802.[5] L. Daukiya et al. Progress in Surface Science 94.1 (2019): 1-20.
