Characterization of epitaxial silicene with Raman spectroscopy

Abstract

Silicene, the silicon equivalent of graphene, is most commonly grown on Ag(111) substrates where it undergoes reconstruction due to the strong interaction between the Si and Ag atoms. We demonstrate through first-principles density functional theory for eight reconstructions that the Raman spectrum is unique for each configuration. We argue that the reconstructions can, in fact, be identified by their Raman spectra and suggest key features within the spectra as points of reference to be used for identification.

Well-defined sub-nanometer graphene ribbons synthesized inside carbon nanotubes

“…[32]. The calculation was successfully used previously for the analysis of doping and strain induced changes of the Raman spectra and gap structure of MoS 2 [51] and silicene [52].…”

“…22 The calculation was successfully used previously for the analysis of doping and strain induced changes of the Raman spectra and gap structure of MoS2 32 and silicene. 33 Optical excitation energies were calculated by solving the Bethe-Salpeter equation within the frame of a quasiparticle self-consistent GW calculation as built in the QUESTAAL code 52 with ladder diagram corrections. 53 Excitation energies were determined by taking the energy values at the maximum of the peaks present in the imaginary part of the macroscopic dielectric function.…”

The Expanding Frontiers of Tip-Enhanced Raman Spectroscopy

“…Silicene, a 2D silicon-based counterpart of graphene epitaxially grown on supporting substrates, such as Ag(111), Ir (111), and Ru(0001), has attracted extensive interest. [216][217][218][219][220] Although Raman spectra of silicene have been intensively studied from both the theoretical and experimental sides, [221][222][223][224][225][226] TERS with high spatial resolution is the most ideal tool to probe silicene's structural and vibrational properties due to the complex formation of diverse Si phases on Ag(111) that depends on growth temperature. In 2017, the Wu group reported TERS of a silicene sheet on Ag (111) with an enhancement factor of $10 9 , and a reported spatial resolution of 0.5 nm, which could be considered the first UHV-TERS study of 2D materials.…”

Optical scanning tunneling microscopy based chemical imaging and spectroscopy

“…And Ru(0001) [116][117][118][119][120]. Raman spectra of silicene have been theoretically as well as experimentally studied [121][122][123][124][125][126]. However, monolayer silicene is known to form diverse coexisting phases.…”