Séminaire proposé par Patrick Soukiassian
Two-dimensional materials are of great interest for the miniaturization of electronic devices and the realization of new functionalities. In particular, silicene, a graphene-like two-dimensional honeycomb structure made of Si atoms, offers new opportunities to scale down further the silicon-based nanotechnologies. The analogy of silicene with graphene is reflected by the existence of Dirac cones in the calculated band structure of its free-standing form [1]. However, in contrast to graphene, silicene was only fabricated in epitaxial forms with electronic and structural properties deviating from those of free-standing silicene. Among the very few substrates on which silicene has been experimentally observed, (0001)-oriented zirconium diboride (ZrB2) thin films grown on Si(111) have the unique capability of promoting the spontaneous and self-terminating growth of a silicene sheet made of atoms segregating from the Si substrate [2,3].
n this talk, I will present an overview of the structural, electronic and chemical properties [4-7] of this exotic form of silicon we investigated experimentally using various techniques including scanning tunneling microscopy and angle-resolved photoemission spectroscopy and by means of density functional theory calculations
[1] S. Cahangirov et al., Phys. Rev. Lett. 102, 236804 (2009).
[2] A. Fleurence et al., Phys. Rev. Lett. 108, 245501 (2012).
[3] A. Fleurence, and Y. Yamada-Takamura, Appl. Phys. Lett. 110, 041601 (2017).
[4] C.-C. Lee, et al., Phys. Rev. B 90, 075422 (2014).
[5] A. Fleurence et al., Appl. Phys. Lett. 108, 151902 (2016).
[6] R. Friedlein et al., Appl. Phys. Lett. 102, 221603 (2013).
[7] B. Warner et al., Advanced Mater. 29, 1703929 (2017).
School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan