Fowler-Nordheim plot characteristics for ZnO virtual field emitter array

Linear and nonlinear Fowler-Nordheim (FN) plots from semiconductors emitters arrays were equally reported by researchers with occasionally inexplicit justification of either behaviour. Interpretation of experimental field emission data depends on explaining the FN plot behaviour from these arrays. The FN plot behaviour was investigated for virtual arrays of ZnO emitters with defined geometries based on fundamental electron tunnelling from semiconductors. The effects of emitters' size distribution, saturation of conduction band (CB) current and contribution of valence band (VB) current on FN plot behaviour were investigated and discussed in detail. Comparison with some experimental results was introduced in support of the discussion. Results showed that saturation of CB current and contribution of VB electrons may not always be manifested as a well-observed deviation from linear characteristic of the FN plot. In addition, the dependence of the CB current on the emitters' geometries was found to affect the FN plot behaviour. The present investigation is thought to be of great importance to field emission community and help for better interpretation of experimental field emission data.