s p 2 -like hybridization of silicon valence orbitals in silicene nanoribbons

Abstract

Silicene nanoribbons grown on a silver (110) substrate have been studied by reflection electron energy loss spectroscopy as a function of the electron beam incidence angle $\alpha$ . The spectra, taken at the Si K absorption edge (1.840 keV), reveal the presence of two distinct loss structures attributed to transitions $1s\to {\pi }^{\ast }$ and $1s\to {\sigma }^{\ast }$ , according to their intensity dependence on $\alpha$ . Such behavior, when compared to graphite, attests the $s{p}^2$ -like hybridization of the silicon valence orbitals in the silicene nanoribbons as is, indeed, for carbon atomic bonds of graphene.