Robust topological insulating property in C<sub>2</sub>X-functionalized III-V monolayers
Two-dimensional topological insulators (TIs) show great potential applications in low-power quantum computing and spintronics due to the spin-polarized gapless edge states. However, the small bandgap limits their room-temperature applications. Based on first-principles calculations, a series of C<sub>2</sub>X (X = H, F, Cl, Br and I) functionalized III-V monolayers are investigated. The nontrivial bandgaps of GaBi-(C<sub>2</sub>X)<sub>2</sub>, InBi-(C<sub>2</sub>X)<sub>2</sub>, TlBi-(C<sub>2</sub>X)<sub>2</sub>and TlSb-(C<sub>2</sub>X)<sub>2</sub>are found to between 0.223 and 0.807 eV. For GaBi-(C<sub>2</sub>X)<sub>2</sub>and InBi-(C<sub>2</sub>X)<sub>2</sub>, the topological insulating properties originate from the<i>s-px,y</i>band inversion induced by the spin-orbital coupling (SOC) effect. While for TlBi-(C<sub>2</sub>X)<sub>2</sub>and TlSb-(C<sub>2</sub>X)<sub>2</sub>, the topological insulating properties are attributed to the SOC effect-induced band splitting. The robust topological characteristics are further confirmed by topological invariants<i>Z</i><sub>2</sub>and the test under biaxial strain. Finally, two ideal substrates are predicted to promote the applications of these TIs. These findings indicate that GaBi-(C<sub>2</sub>X)<sub>2</sub>, InBi-(C<sub>2</sub>X)<sub>2</sub>, TlBi-(C<sub>2</sub>X)<sub>2</sub>and TlSb-(C<sub>2</sub>X)<sub>2</sub>monolayers are good candidates for the fabrication of spintronic devices.
Authors
- Mengmeng Han (ORCID: https://orcid.org/0000-0001-9504-9971)
- Xianghong Xue
- Rui Gao (ORCID: https://orcid.org/0000-0002-4704-206X)
- Haoyu Wang (ORCID: https://orcid.org/0000-0002-8905-822X)
- Nannan Han (ORCID: https://orcid.org/0000-0002-7783-9950)
- Zhihua Lin
- Bingzhuo Yang
Institutions
- Northwestern Polytechnical University (CN)
- Xi'an University of Technology (CN)
- China Railway Construction Corporation (China) (CN)
Publication Details
- Journal
- Nanotechnology
- Published
- 2024-09-27
- DOI
- https://doi.org/10.1088/1361-6528/ad8098
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- China Postdoctoral Science Foundation
- Key Research and Development Projects of Shaanxi Province