Solonenko, D.Dzhagan, V.Cahangirov, S.Bacaksiz, C.Sahin, H.Zahn, D. R. T.Vogt, P.2018-04-122018-04-1220172469-9950http://hdl.handle.net/11693/37133We report on the hydrogenation of (3×3)/(4×4) silicene epitaxially grown on Ag(111) studied by in situ Raman spectroscopy and state-of-the-art ab initio calculations. Our results demonstrate that hydrogenation of (3×3)/(4×4) silicene leads to the formation of two different atomic structures which exhibit distinct spectral vibrational modes. Raman selection rules clearly show that the Si atoms undergo a rehybridization in both cases from a mixed sp2-sp3 to a dominating sp3 state increasing the distance between the two silicene sublattices. This results in a softening of the in-plane and a stiffening of the out-of-plane phonon modes. Nevertheless, hydrogenated epitaxial silicene retains a two-dimensional nature and hence can be considered as epitaxial silicane. The level of hydrogenation can be determined by the intensity ratio of the Raman modes with different symmetries. © 2017 American Physical Society.EnglishChemisorption2-dimensional systemsDensity functional theoryRaman spectroscopyArticle10.1103/PhysRevB.96.235423