Atomic structures of silicene layers grown on Ag(111): scanning tunneling microscopy and noncontact atomic force microscopy observations.
Silicene, the considered equivalent of graphene for silicon, has been recently synthesized on Ag(111) surfaces. Following the tremendous success of graphene, silicene might further widen the horizon of two-dimensional materials with new allotropes artificially created. Due to stronger spin-orbit coupling, lower group symmetry and different chemistry compared to graphene, silicene presents many new interesting features. Here, we focus on very important aspects of silicene layers on Ag(111): First, we present scanning tunneling microscopy (STM) and non-contact Atomic Force Microscopy (nc-AFM) observations of the major structures of single layer and bi-layer silicene in epitaxy with Ag(111). For the (3 × 3) reconstructed first silicene layer nc-AFM represents the same lateral arrangement of silicene atoms as STM and therefore provides a timely experimental confirmation of the current picture of the atomic silicene structure. Furthermore, both nc-AFM and STM give a unifying interpretation of the second layer (√3 × √3)R ± 30° structure. Finally, we give support to the conjectured possible existence of less stable, ~2% stressed, (√7 × √7)R ± 19.1° rotated silicene domains in the first layer.
Aix-Marseille Université, CNRS, CINaM UMR 7325, 13288 Marseille, France. resta@cinam.univ-mrs.fr
Andrea
A
Resta
Thomas
T
Leoni
Clemens
C
Barth
Alain
A
Ranguis
Conrad
C
Becker
Thomas
T
Bruhn
Patrick
P
Vogt
Guy
G
Le Lay
D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D018625:Microscopy, Atomic Force / Q000379:methods*; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D008968:Molecular Conformation; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
D012834:Silver; D012825:Silicon