Vacancy defects- and strain-tunable electronic structures and magnetism in two-dimensional MoTe2: Insight from first-principles calculations

Abstract

Report on theoretical study of the vacancy defect and biaxial strain effects on the structural, electronic and magnetic properties of monolayer MoTe2 by performing first-principles calculations. We further estimated the formation energies for VTe, VTe2, VMo, VMo2, VMoTe3, VMoTe6 defective configurations in which Te vacancy displays the lower formation energy under both Mo‐ and Te‐rich conditions, indicating that they can presumably be created during the synthesis. Our results show that VTe, VTe2, VMo2, VMoTe3, VMoTe6 vacancy configurations are nonmagnetic, while VMo vacancy introduces a magnetic moment of 2.53 µB, which rises from the p states of the six neighboring Te atoms surrounding the Mo point defect. Interestingly, the nonmagnetic VTe and VMoTe3 defective systems display a change in the magnetic state when the biaxial tensile strain is applied. This change is owing to the relative variation of spatial position of atoms, which leads to further delocalization of electrons and modification of bonding influences around the vacancies. Our findings pointed that the vacancy defect and strain can engineer the electronic and magnetic properties of monolayer MoTe2, making it as a potential candidate for spintronic applications.