The effect of substrate and external strain on electronic structures of stanene film

Abstract

From first-principles calculations, the effects of h-BN and AlN substrates on the topological nontrivial properties of stanene are studied with different strains. We find that the quantum spin Hall phase can be induced in stanene film on a h-BN substrate under a tensile strain of between 6.0% and 9.3% with a stable state confirmed by the phonon spectrum, while for stanene on 5 × 5 h-BN, the quantum spin Hall phase can be preserved without strain. However, for stanene on a AlN substrate, the quantum spin Hall phase cannot be found under compressive or tensile strains less than 10%, while for 2 × 2 stanene on 3 × 3 AlN, the compressive strain needed to induce the quantum spin Hall phase is just 2%. These theoretical results will be helpful in understanding the effect of substrate and strain on stanene and in further realizing the quantum spin Hall effect in stanene on semiconductor substrates.

Structural and electronic properties of two-dimensional stanene and graphene heterostructure

“…For the monolayer graphene and free-standing low-buckled stanene, the lattice constants we obtained from LDA are 2.45 and 4.56 Å, respectively, which agree well with the reported values of 2.46 and 4.67 Å for graphene and stanene, respectively [53, 54]. Note that the lattice mismatch is as large as 7% even when a supercell consisting of 2 × 2 lateral periodicity of graphene and 1 × 1 stanene is employed.…”

Quasiparticle and optical properties of strained stanene and stanane

“…Previous studies on the fundamental band gaps of stanene and stanane are mainly at the standard density functional theory (DFT) level. DFT calculations indicate band gaps of 0.07 and 0.57 eV for stanene and stanane, respectively 9, 14, 15 . After applying the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, the value increases to 0.1 and 1.0 eV, respectively 16, 17 .…”

“…Ezawa pointed out that stanene belongs to quantum spin Hall (QSH) insulators due to its SOC effect 12 . The band gap of 0.3 eV opened by its large intrinsic spin-orbit interaction suggests the practical applications at room temperature for integrated circuits 13, 14 . (ii) The low-dimensional systems have strong many-body interactions due to the reduced screening and geometrical confinement.…”

Band gap opening in stanene induced by patterned B–N doping

“…Stanene shows a band gap of 0.1 eV 6 ( Figure S1(a), Supporting Information) after inclusion of SOC, which is very much in agreement with the previous reports on stanene. 24,59 …”