Model calculation for enhancement factor of a gated field emission nanotube

The field enhancement factor of gated nanotube with opened top was analytically calculated by the electrostatic method. The effect of geometrical parameters of the device on their field enhancement factor was investigated, including the gate-hole radius, gate-anode distance, and nanotube radius. The theoretical analysis shows that the enhancement factor increases greatly with the decrease of gate-hole radius. However, if the gate voltage is zero, the factor increases with the increase of gate-hole radius, and finally reaches a constant, which increases with the increase of nanotube length L. The enhancement factor beta gets larger when the nanotube radius gets smaller. As the gate-anode distance d(2) is finite, the beta will decrease with the increase of d(2). If the d(2) is infinite, the effect of gate-anode distance on beta can be ignored. All the results of theoretical calculation can provide useful information in the fabrication and design of the gated nanotube cold cathode for field emission display panels and other nanoscale triode devices. (c) 2007 American Institute of Physics.