Quasi-Free-Standing Features of Stanene/Stanane on InSe and GaTe Nanosheets: A Computational Study

Abstract

Two-dimensional tin and its iodized derivative, called stanene and stanane, are intriguing nanomaterials as quantum spin Hall (QSH) insulators. A recent experiment on stanene has found that the strong interaction from substrates will disturb the Dirac cones and cause a metallicity problem into stanene [F. Zhu et al. Nat. Mater. 2015, 14, 1020. On the basis of van der Waals density functional calculations, we find that stanene and stanane can form commensurate van der Waals heterosheets with InSe and GaTe layers, which exhibit quasi-free-standing features with comparable spin−orbit coupling gaps to isolate values. Particularly, the supported stanane is still a large-gap QSH insulator, for which the substrates induce a tunable Rashba splitting that can be modulated by changing the interlayer distance of heterosheets. Our study demonstrates that layered III−VI chalcogenides are promising substrates for stanene and stanane, on which their intrinsics features can be well preserved for potential applications in topological materials and quantum manipulated devices.

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

“…Various approaches have been taken to modulate the electronic properties of stanene. [24][25][26][27][28] Tang et al 27 demonstrated that functionalization on stanene can open up the gap. Furthermore, the substrate plays an important role to tune the electronic properties of stanene due to the strong interaction.…”

“…Furthermore, the substrate plays an important role to tune the electronic properties of stanene due to the strong interaction. 25,29 Electronic properties of stanene are affected by the substrate because it induces band inversion in the bonding and antibonding states of stanene, which opens up the band gap in stanene. 27 Furthermore, van der Waals heterostructure of stanene modulates its electronic properties.…”

Strain-Tunable Electronic Properties and Band Alignments in GaTe/C2N Heterostructure: a First-Principles Calculation

“…Quasi-2D GaTe/GaSe heterostructure was created by transferring exfoliated few-layer GaSe onto bulk GaTe sheets and found to form type I band alignment at the interface [ 29 ]. The GaTe/SnI heterostructure was verified to be a large-gap quantum spin Hall insulator and exhibits a noticeable Rashba splitting that can be modulated by changing the interlayer distance of heterosheets [ 30 ]. In addition, construction of semiconductor/C 2 N heterostructures, such as g-C 3 N 4 /C 2 N [ 31 ], MoS 2 /C 2 N [ 32 ], and CdS/C 2 N [ 33 ], demonstrated an enormous potential for promoting the photocatalytic performance of C 2 N due to the efficient separation of the electron-hole pairs, thereby restraining the recombination of photogenerated carriers.…”

Tailoring topological states in silicene using different halogen-passivated Si(111) substrates

“…This fascinating proposal immediately boosted the search for 2D TIs, although it has been ruled out for the case of graphene itself due to the negligible SOI. In recent years, besides QW structures, various atomically thin mono or few layers have been studied mostly theoretically to peruse nontrivial topological phases in 2D materials [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] . These atomically thin crystals usually consist of either an element from group III to group VII or some certain transition metal compounds, although among them there are complex structures like organometallic lattices (for a decent review see Ref.…”