Nanowires for Efficient Electron Field Emission and Limitations of the Fowler-Nordheim Model*

We report on top-down nanofabricated Ni₃Si₂ nanowires and test of their electron field emission capabilities. The results include low turn-on electric field, E_ON, moderate work function, Φ, and the field enhancement factor, β, the last parameter being customizable through nanofabrication. The growth and nanofabrication processes ensure a stable Ni-to-Si stoichiometry, and we demonstrate highly repeatable J vs. E curves. We also report on the issues ahead in the field of nanowires-based electron mission, as there are quantitative limitations of the applicability of the Fowler-Nordheim (FN) model, which will become increasingly apparent as we continue to optimize field emission of electrons. To this end, we suggest adding the studies of surface-to-volume ratio effects of the nanowires as another standard for comparison, in order to lead to the input form of the density of states as quantum effects becoming more prominent. This is relevant for increasingly quantum nature of electrons field emission, and calls for analysis of experiments without FN framework.