Synthesis and properties of 2D graphenic materials (hBN, silicène)

Since the discovery of graphene and the tremendous advancement in this field of research, strong efforts have been invested to search for theoretical and experimental similar 2-dimensionnal new materials. In this project, we will focus on the preparation of 2D hexagonal boron nitride and silicene. Such 2D materials will be formed by the technique that we have developed since three years now at ICube/MaCEPV in Strasbourg by elemental ionic implantation (B, N, Si) in a metallic matrix (like Ni, Cu, Ag) at moderate temperature. In this versatile technique of preparation the exact amount of these elements will diffuse to the surface or to the interface, according to the deepness of the implantation. Nitrogen and boron can be coimplanted with the same dose at the same depth and then would form through diffusion the hBN, a stoichiometry which is elsewhere difficult to obtain from gaseous precursors. In the case of silicene, the 2D sp2 hybridized form of silicon does not exist at all in the nature and is by far not stable in the air environment. The advantages of the implantation method for silicene are that the implanted silicon can be safely handled in a metallic matrix like Ag (111) film, without formation of silicide or absorption, without oxidation through air exposition, and the UHV diffusion towards surface can be controlled. Once the surface silicene is formed, the electronic properties of such materials will be investigated by UHV by ARPES, STM in the LS2M laboratory in Mulhouse (collaboration with J.P. Bubendorff).