Phase Engineering of Epitaxial Stanene on a Surface Alloy

Abstract

Stanene is a notable two-dimensional topological insulator with a large spin− orbit-coupling-induced band gap. However, the formation of surface alloy intermediates during the epitaxial growth on noble metal substrates prevents the as-grown stanene from preserving its intrinsic electronic states. Here, we show that an intentionally prepared 3 3 × Au 2 Sn(111) alloy surface is a suitable inert substrate for growing stanene without the further formation of a complicated surface alloy by scanning tunneling microscopy. The Sn tetramer and clover-shaped Sn pentamer are intermediates for the black-phosphorene-like Sn film at a substrate temperature of <420 K, which transforms to a blue-phosphorene-like stanene with a lattice constant of 0.50 nm above 500 K. First-principles calculations reveal that the epitaxial Sn layer exhibits a lattice registry growth mode and holds a direct energy gap of ∼0.4 eV. Furthermore, interfacial chargetransfer-induced significant Rashba splitting in its electronic structure gives it great potential in spintronic applications.

Silicene’s pervasive surface alloy on Ag(111): a scaffold for two-dimensional growth

“…It is even questionable whether the 2D-Si can be regarded as 2D material at all, as it would be making strong chemical bonds well outwith the 2D plane that defines the layer. Finally, the role that we propose for the Si-Ag alloy in the growth of silicene, and the role that the Ge-Ag, Sn-Ag and Sn-Au alloys play in the growth of germanene and stanene [32,61,79], suggest that the alloy scaffolding of 2D materials may be a common phenomenon on metal surfaces and have implications for delaminating these films from their growth substrate, which has been achieved for hydrogenated and oxidized silicene and gemanene [80]. Ultimately, silicene on Ag(111) may have more in common with Ca intercalated Si or Ge [81,82], than ideal freestanding silicene.…”

Investigating the enhancement of lung cancer sensing: the effect of edge halogenation in armchair stanene nanoribbons

“…Stanene is a monolayer of Sn atoms arranged in a hexagonal graphene-like structure. Extensive theoretical [13][14][15] and experimental 16,17 studies on stanene have been conducted since its first synthesis in 2015. 18 Unlike graphene, stanene exhibits hybridization, which is a mixture of sp 2 and sp 3 orbitals, contributing to its high reactivity.…”