Field-enhancement factor of a carbon nanotube cold cathode triode

摘要

To estimate the field-enhancement factor, the model system of floated sphere in triode configuration of the carbon nanotube was proposed, and the actual electric field and field enhancement factor at the apex of carbon nanotube were calculated with the image charge method analytically. The field-enhancement factor given as β=3+ρ+W, whereρ is the aspect ratio of the carbon nanotube, and W is the function of geometrical parameters and the anode and gate voltages. The geometrical parameters affects the field-enhancement factor very much, such as the field-enhancement factor decreased rapidly with the increasing of top radius of carbon nanotube, gate-cathode distance and gate-hole size. The field-enhancement factor could be improved via concocting the gate-electrode.