Field enhancement factor for the floating sphere model of the nanotube array in parallel-plate geometry

Excellent electron-field emission properties of carbon nanotubes (CNTs) attract essential scientific and practical interests. The small gap between top of the emitter and the anode essentially increases the field enhancement factor. The screening effect reduces the field emission current of a CNT placed in an array of CNTs. We have derived explicit analytical expression of the field enhancement factor for the “floating sphere” model of CNT array in parallel-plate geometry. Comparison with other theoretical calculations is shown. We have generalized the published experimental data.