Silicene, germanene and stanene have attracted considerable interest since the birth of silicene in 2012 as emerging synthetic two-dimensional(2D) electronic materials for the post graphene era[1]. These novel Si, Ge and Sn allotropes are artificially created by molecular beam epitaxy, since, at variance with graphene, which inherits from graphite, they have no parent crystal in nature. They are considered as promising candidates for ultimate scaling of nanoelectronic devices[2,3]. Indeed, the recent fabrication of the first silicene field effect transistors operating at room temperature demonstrates their potential as emerging 2D electronic materials [4].
In this talk, I will present the archetype 3×3 silicene phase formed on a silver(111) substrate[1], its sister phases and the growth of multilayer silicene, which hosts Dirac fermions and which is stable in ambient air, protected by its ultra-thin native oxide[5]. The recent synthesis of single layer germanene and stanene, near room temperature 2D topological insulators, will be also presented[6,7,8], while multilayer germanene will be further addressed[9].
Finally the applications envisaged with these emerging 2D materials will be discussed.

1. P. Vogt et al., Phys. Rev. Lett., 108, 155501(2012).
2. A. Dimoulas, Microelectronic Engineering, 131, 68(2015).
3. G. Le Lay, Nature Nanotechnology, 10, 202(2015).
4. Li Tao et al., Nature Nanotechnolgy, 10, 227(2015).
5. P. De Padova et al., 2D Mater., 1, 021003(2014).
6. M.E. Dávila et al., New J. Phys., 16, 095002(2014).
7. M. Derivaz et al. Nano Lett., 15, 2510(2015).
8. Feng-feng Zhu et al., Nature Mater., 14, 1020(2015).
9. M. E. Davila et al., in revision.