Si Ultrathin Films on Silver Surfaces: An Intriguing Epitaxial System
Résumé
The reported synthesis of two dimensional Si sheets on silver substrates with structural and electronic properties attributed to the formation of silicene recently aroused considerable interest. We present here a review of the state of art concerning the growth of Si ultrathin films on Ag(110), the first system interpreted within the framework of silicene models. In particular, we report in situ measurements using local and macroscopic probes to characterize the structural and optical properties of the Si layer consisting of self-organized Si nanoribbons grown on Ag(110). Our results, together with recent reported theoretical investigations, provide compelling evidence that the Si sheet cannot be interpreted within the framework of current silicene models and that the observed properties result from a subtle interplay between the Si overlayer and the Ag(110) substrate. Finally, we show that the Si grating can be used a novel Si template for the growth of one dimensional nanostructures.