title: Alternative Route to Silicene Synthesis via Surface Reconstruction on h-MoSi2Crystallites.
abstract: Silicene is a two-dimensional material with a Dirac-type band structure and it is particularly attractive due to its potential for integration with Si-based technology. The primary focus has been to grow single silicene layers and understand how the electronic structure is affected by the substrate and the phase transition between low- and high-buckling configurations. Typically, silicene is synthesized by depositing monolayer amounts of silicon onto a heated Ag(111) surface; however, other growth substrates such as Ir(111) and ZrB2have been studied recently. We present a novel route for silicene synthesis via a high-temperature surface reconstruction of hexagonal-MoSi2nanocrystallites. The h-MoSi2crystallites are formed by annealing of thin Mo-layers on Si(100)-(2 × 1) and their crystallographic orientation is controlled via an epitaxial relation with the Si-substrate. The (0001) plane of h-MoSi2is comprised of Si-hexagons with a Mo atom residing in the center. Annealing above approximately 650 °C causes the (0001) plane to undergo a surface reconstruction process leaving a honeycomb pattern on the surface of these crystallites as shown by scanning tunneling microscopy. We define this surface layer as a silicene-like reconstruction (SLR), and a detailed geometric analysis of our structure yields a perfect match with the (√3 × √3)R30° silicene superstructure in a low-buckled configuration (ABA̅). Scanning tunneling spectroscopy data of the SLR, Si(001)-(2 × 1) and h-MoSi2surfaces agree with this interpretation. The formation of this structure on a transition metal silicide opens up the opportunity for integration into Si-based devices without the necessity for a transfer scheme.
authors.affiliation: Department of Materials Science and Engineering, University of Virginia , 395 McCormick Road, Charlottesville, Virginia 22904, United States.
authors.forename: Cameron
authors.initials: C
authors.lastname: Volders
authors.affiliation: Department of Materials Science and Engineering, University of Virginia , 395 McCormick Road, Charlottesville, Virginia 22904, United States.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Monazami
authors.affiliation: Department of Materials Science and Engineering, University of Virginia , 395 McCormick Road, Charlottesville, Virginia 22904, United States.
authors.forename: Gopalakrishnan
authors.initials: G
authors.lastname: Ramalingam
authors.affiliation: Department of Materials Science and Engineering, University of Virginia , 395 McCormick Road, Charlottesville, Virginia 22904, United States.
authors.forename: Petra
authors.identifier: 0000-0002-4544-5906
authors.initials: P
authors.lastname: Reinke
keywords: Si(001); Silicene; disilicide; reconstruction; scanning tunneling microscopy