|approved||osi_11_borensztein.pdf||2015-04-13 10:51:41||Yves Borensztein|
Author: Yves Borensztein
Requested Type: Pre-Selected Invited
Submitted: 2015-03-13 12:46:58
Co-authors: Romain Bernard, Hervé Cruegel, Laurence Masson, Geoffroy Prevot
Institute for NanoSciences in Paris-Univ. Paris 6
4 place Jussieu
Silicene single layers and multilayers have been receiving an increasing interest since some authors reported its elaboration on several substrates, in particular on single Ag crystals. Although the observed symmetry is in favor of the actual formation of the single silicene layer, number of questions are still unclear.
By combining real-time STM and optical surface reflectance spectroscopy during Si deposition, we show a strong interaction between the Ag substrate and the silicon layer, with Si-Ag intermixing during the formation ; this could explain that the single layer appears to lose the expected electronic and optical properties of silicene.
Silicene multilayers are also controversial. Optical measurements indicate that the silicon multilayer has an optical response very close to the one of diamond-like silicon and different from what is expected for a silicene multilayer or "silicite" film. Moreover, our Auger spectroscopy measurements indicates that Ag atoms remain on the very surface, questioning the origin of the observed reconstruction.