Large gap two-dimensional topological insulators with prominent Rashba effect in ethynyl functionalized Ⅲ-Bi Buckled-Honeycomb monolayers. (October 2021)

• Record Type: Journal Article
• Authors: Wang, Yonghu; Lei, Shuangying; Wan, Neng; Yu, Hong; Chen, Jie
• Is Part Of: Superlattices and microstructures. Volume 158(2021)
• Publication Date: 2021-10
• Subjects: First-principles -- Topological insulators -- Quantum spin hall -- Edge states -- Rashba effect; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2021.107026
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: Recently, two-dimensional topological insulators have attracted extensive attention because of their excellent electronic transport performance and easy integration into electronic devices. However, the small bandgap limits their room-temperature application. Based on first-principles calculations, we predict that the ethynyl functionalized GaBi/InBi monolayers are topological insulators with large bandgap ( E g = 0.512 e V ) and significant Rashba SOC effect ( α R = 2.819 eVÅ ). The topological phases, which originate from s-p x, y band inversion induced by chemical bonding, can be maintained within the large-range biaxial strain. Additionally, the h -BN is found to be an ideal substrate for the growth of these QSH insulators. These findings indicate that the ethynyl functionalized Ⅲ-Bi monolayers are expected to be candidate materials for spintronics and quantum computing. These findings indicate that the ethynyl functionalized Ⅲ-Bi monolayers are expected to be candidate materials for spintronics and quantum computing. Highlights: We predict that the ethynyl functionalized GaBi/InBi monolayers are topological insulators with large bandgap ( E g = 0.512 eV ) and significant Rashba SOC effect ( α R = 2.819 eVÅ ) . We research the strain engineering and explain the change in topology phase through evolution of orbitals. We study the significant Rashba SOC effect and the electric field impact. The h -BN is found to be an ideal substrate for the growth of these QSH insulators.