Reduction of Work Function in Nanostructured Modern Cathodes for the Field Emission (Based on the Example of Tungsten Oxide W18O49 "Nanopencils")

M.V. Strikha; I.Ye. Oliynyk

doi:10.15330/pcss.26.1.190-195

Authors

M.V. Strikha Taras Shevchenko National University of Kyiv, Faculty of Radiophysics, Electronics and Computer Systems, Kyiv, Ukraine; V.Ye. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
I.Ye. Oliynyk Taras Shevchenko National University of Kyiv, Faculty of Radiophysics, Electronics and Computer Systems, Kyiv, Ukraine

DOI:

https://doi.org/10.15330/pcss.26.1.190-195

Keywords:

Work function, field emission, nanostructured cathodes

Abstract

Within the framework of a simple analytical model, an expression has been obtained that allows to calculate the work function near the tips of a nanostructured cathodes used in modern field emission devices. Numerical evaluations performed for tungsten oxide W₁₈O₄₉ “nanopencils” show that taking into account the considered decrease in the surface electron gas density near the nanotip leads to a decrease in the “bulk” value of the work function (~4.55 eV) by approximately 10%. This effect must be taken into account when calculating the emission current density according to the Fowler-Nordheim formula. It (as well as the electric field enhancement due to the tip geometry) leads to an increase in the emission current density and a decrease in the emission turn-on field.

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