title: van der Waals Heteroepitaxy of Germanene Islands on Graphite.
abstract: We fabricated flat, two-dimensional germanium sheets showing a honeycomb lattice that matches that of germanene by depositing submonolayers of Ge on graphite at room temperature and subsequent annealing to 350 °C. Scanning tunneling microscopy shows that the germanene islands have a small buckling with no atomic reconstruction and does not give any hints for alloy formation and hybridization with the substrate. Our density functional theory calculations of the structural properties agree well with our experimental findings and indicate that the germanene sheet interacts only weakly with the substrate underneath. Our band structure calculations confirm that the Dirac cone of free-standing germanene is preserved for layers supported on graphite. The germanene islands show a small but characteristic charge transfer with the graphite substrate which is predicted by our ab initio simulations in excellent agreement with scanning tunneling spectroscopy measurements.
authors.affiliation: Department of Materials, ETH Zurich , Hönggerbergring 64, Zürich 8093, Switzerland.
authors.forename: Luca
authors.initials: L
authors.lastname: Persichetti
authors.affiliation: CNRS-LPICM, Ecole Polytechnique, Université Paris-Saclay , 91128 Palaiseau, France.
authors.forename: Fatme
authors.initials: F
authors.lastname: Jardali
authors.affiliation: CNRS-LPICM, Ecole Polytechnique, Université Paris-Saclay , 91128 Palaiseau, France.
authors.forename: Holger
authors.initials: H
authors.lastname: Vach
authors.affiliation: Dipartimento di Fisica, Università di Roma "Tor Vergata" , Via della Ricerca Scientifica 1, 00133 Roma, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Sgarlata
authors.affiliation: CNRS, Aix-Marseille Université, IM2NP, UMR 7334 , Campus de St. Jérome, 13397 Marseille, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Berbezier
authors.affiliation: Dipartimento di Fisica, Università di Roma "Tor Vergata" , Via della Ricerca Scientifica 1, 00133 Roma, Italy.
authors.forename: Maurizio De
authors.initials: MD
authors.lastname: Crescenzi
authors.affiliation: Dipartimento di Fisica, Università di Roma "Tor Vergata" , Via della Ricerca Scientifica 1, 00133 Roma, Italy.
authors.forename: Adalberto
authors.initials: A
authors.lastname: Balzarotti