Facing the interaction of adsorbed silicon nano-ribbons on silver

Abstract

The atomic structure is one key property for any material. Despite great efforts during the last few years unveiling the internal structure of silicon nano-ribbons, analysis of the interfacial structure and bonding was neglected. We report on a comprehensive photoelectron spectroscopy and photoelectron diffraction study that reveals the weak interaction of silicon nano-ribbons with the underlying silver substrate identifying the specific locations of the individual silicon, as well as silver atoms. Furthermore, we provide unique experimental evidence that clarifies the origin of the two distinct chemically shifted components in the silicon photoelectron spectra.

Silicene Nanoribbons on an Insulating Thin Film

“…In Figure 5a and that the Si-NaCl interaction is weak. This contrasts clearly with previous XPS studies of silicon on silver surfaces that showed two distinct components resulting from the two Si-Si and Si-Ag environments [9,10,52] . Figure 6 shows the modulus and the imaginary part of the Fourier transform of k 3 X(k) for bulk silicon and for the silicon layer grown on NaCl/Ag(110) surface.…”

“…Given that Si atoms are adsorbed on top of the NaCl film and that the Si-NaCl interaction is weak. This contrasts clearly with previous XPS studies of silicon on silver surfaces that showed two distinct components resulting from the two Si-Si and Si-Ag environments [9,10,52] . EXAFS measurements recorded at the Si K-edge provide complementary information on the local structure of the 2D silicon layer grown on NaCl/Ag(110) surface.…”

“…This contrasts clearly with previous XPS studies of silicon on silver surfaces that showed two distinct components resulting from the two Si‐Si and Si‐Ag environments. [ 9,10,52 ]…”

“…It is interesting to note that in ref. [ 52 ] , an interatomic distance of 2.7 Å was attributed to the Si‐Ag bond. [ 53 ] In our study, this particular distance is not observed indicating that Si‐Ag bonds are absent.…”

Optical properties of silicene, Si/Ag(111), and Si/Ag(110)

“…1(d)) was proposed for the nanoribbon structures 24 that satisfies DFT total energy calculations and high-resolution STM, core-level photoemission, and grazing-incidence xray diffraction experiments. 24,25 Further confirmation of a pentamer chain structure has recently been provided by photoelectron spectroscopy (XPS) and angle-resolved photoelectron diffraction (XPD) experiments, 26 as well as non-contact atomic force microscopy (nc-AFM) and tip-enhanced Raman spectroscopy (TERS). 27 Similar to Si/Ag(111), the Si/Ag(110) system thus consists of silicon adlayers strongly bonded to the Ag surface; nonethe-less there is little evidence to suggest that these structures retain any of the electronic features of a silicene-like layer, even when peeled off the substrate.…”