Study by EXAFS of the local structure around Si on silicene deposited on Ag(1 1 0) and Ag(1 1 1) surfaces

The local structure around the silicon atoms of silicene deposited onto Ag(1 1 0) and Ag(1 1 1) has been determined by extended x-ray absorption fine structure spectroscopy at the silicon K-edge. This study shows that silicon atoms are not in a flat honeycomb network locally buckled, but that this structure mimics the double Si(1 1 1)-plane of crystalline silicon with almost the same first and second interatomic distances (2.35 and 3.83 Å) on a regularly buckled geometry. Moreover the results evidence silver atoms at a well-defined distance from the silicon ones, a signature for an interaction between the silicene sheet and silver atoms released from the substrate.