Field emission properties of two-dimensional VS₂-ZnO composites: A density functional theory study

The electronic structures and field emission properties of VS₂-ZnO composites were studied using density functional theory calculations. The possible effect of the external electric field on the important electronic parameters including binding energies, charge transfer, distributions of near-gap electronic states, work functions and ionization potentials of VS₂-ZnO composites were also investigated. The calculation results prove that binding energies gradually increase with the increasing of the electric field and the composites have field-enhanced stability. The charge accumulation of S atoms from VS₂ contributes directly to the field emission properties of the two dimensional VS₂ materials. Moreover, the electric field can induce the decrease of work function and ionization potential for VS₂-ZnO composites. These results prove that VS₂-ZnO composites could be used as a promising candidate for applications in field emission devices.