High Stability and Inoxidizability of Monolayer Topological Insulator ZrTe₅

Abstract

Two-dimensional (2D) topological materials have attracted huge attention due to their unique symmetry-protected topological edge states. However, their instability in the ambient environment significantly hinders their further applications. In this work, we systemically investigated H2O or O2 molecules in tuning the properties of 2D monolayer ZrTe5 materials using first-principles calculations. Our results suggest that the monolayer ZrTe5 can be easily exfoliated from its bulk phase in the experiment. Moreover, H2O is physisorbed while O2 prefers chemisorption in monolayer ZrTe5, but the dissociation barrier of O2 is 0.87 eV significantly beyond that of black phosphorene, revealing that the monolayer ZrTe5 has high stability. Importantly, its remaining topological properties are retained with symmetry-protected edge states even though the O coverage is up to 33% on the monolayer ZrTe5 surface. We analyze the reason that the contributions near the Fermi level mainly originated from the 2p orbitals of Te atoms and the time-reversal symmetry of monolayer ZrTe5 is not changed without/with O adsorption. Our findings provide a desirable 2D topological insulator under ambient conditions for application in low-power-consumption spintronic devices.