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. (C) 2015 Elsevier B.V. All rights reserved.