Alternative Route to Silicene Synthesis via Surface Reconstruction on h-MoSi₂ Crystallites

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 ZrB have been studied recently. We present a novel route for silicene synthesis via a high-temperature surface reconstruction of hexagonal-MoSi nanocrystallites. The h-MoSi crystallites 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-MoSi is 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-MoSi surfaces 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.

Ge2Pt hut clusters: A substrate for germanene

“…In a later study, MoSi 2 clusters were grown on Si using the same method. 16 These MoSi 2 clusters also exhibit a honeycomb lattice which the authors attributed to be a silicene layer. 16 Similar to the Ge 2 Pt system, the role of the clusters as substrate was still not addressed.…”

“…16 These MoSi 2 clusters also exhibit a honeycomb lattice which the authors attributed to be a silicene layer. 16 Similar to the Ge 2 Pt system, the role of the clusters as substrate was still not addressed. In both studies, the focus was on flat clusters, as small height variations are more suitable for scanning tunneling microscopy (STM) study.…”

Epitaxial Growth of Main Group Monoelemental 2D Materials

“…The successful growth of germanene via segregation indicates that the deposition of thin metal films on semiconductors is an effective way to grow ME2DMs. Another example is the segregation of silicene by annealing, through which thin Mo layers were deposited on a Si(100) surface at 923 K. [ 131 ]…”

Insight into the structures, melting points, and mechanical properties of NbSi2 from first‐principles calculations

“…Transition‐metal disilicides (TMSi 2 ) as high‐temperature ceramic materials have received widespread attention because of their moderate density, thermal stability, excellent strength, good oxidation, and creep resistance, which can endow them with variety of applications in high‐temperature devices, such as industrial gas burners, thermal barrier coating, and advanced aerospace turbine blades, etc . The structural stability and mechanical properties of TMSi 2 are of primary importance, since they are the foundation of application.…”