Atomic Structures of Silicene Layers Grown on Ag(111): Scanning Tunneling Microscopy and Noncontact Atomic Force Microscopy Observationsd

作者：Resta Andrea^*; Leoni Thomas; Barth Clemens; Ranguis Alain; Becker Conrad; Bruhn Thomas; Vogt Patrick; Le Lay Guy

来源：Scientific Reports, 2013, 3(1): 2399.

DOI：10.1038/srep02399

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 x 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 (root 3 x root 3)R +/- 30 degrees structure. Finally, we give support to the conjectured possible existence of less stable, similar to 2% stressed, (root 7 x root 7)R +/- 19.1 degrees rotated silicene domains in the first layer.

• 出版日期2013-8-9