Influence of the optoelectronic properties of F-MoTe₂ systems under the combined action of an external electric field and biaxial tensile-compressive deformation: a first-principles study

The effects of an applied electric field on the electronic structure, charge transfer, and optical characteristics of molybdenum telluride (MoTe2) systems doped with halogen F atoms during biaxial tensile-compressive deformation were explored using first-principles approaches. The results show that the MoTe2 system exhibits an upward shift of the Fermi energy level and a downward shift of the conduction band when crossing the Fermi energy level due to the doping of halogen F atoms. Subsequently, we applied an electric field of -0.4 eV~-0.4 eV to the F-MoTe2 system. The change of the F-MoTe2 system under the electric field effect is very small. This result indicates that the F-MoTe2 system can be stabilized in this range. Subsequently, we chose to apply a biaxial tensile-compressive deformation of -14%-14% to the F-MoTe2 system under the action of an electric field of +0.4 eV. The F-MoTe2 system underwent a transition from a semiconductor to a metal, with an increase in the carrier concentration and a good shift in electrical conductivity. The compressive strain gives better results than the tensile strain. In terms of optical characteristics, the absorption and emission peaks of the F-MoTe2 system are blueshifted under the combined effect of electric field and stress.