We study the role of equi-biaxial strains on the electronic structure in pnictogen chalcogenides Bi2Se3, Bi2Te3, and As2Te3. Bi2Se3 and Bi2Te3 are topological insulators, and As2Te3 is an insulator with a relatively small bandgap. Based on the results of density functional theory calculations including van der Waals corrections, we demonstrate that a topological insulator (TI) state in As2Te3 can be induced by an epitaxial (in-plane) tensile misfit strain of 1%. Furthermore, we find overall that the effect of the misfit on the bandgap is larger for As2Te3 than for Bi2Se3 and Bi2Te3. We attribute this to a complex interplay between the misfit strain, spin–orbit coupling, and the relaxation of surface atomic layers. Our findings indicate that As2Te3 is more suitable than Bi2Se3 and Bi2Te3 for potential applications of strain-induced switching of TIs.

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