Electrical Field Enhancement in Carbon Nanotube-Based Electron Field Cathodes

The problem of evaluating the field amplification factor in electron field emitters on the basis of carbon nanotubes (CNT) has been considered. The electrostatic problem of determination of the field amplification factor for CNTs having various structures of the tip, depending on the tilting angle in regard to the cathode plane as well as on the inter-electrode distance, has been resolved. The dependence of the field amplification factor for vertically aligned CNTs comprising an array on the intertube distance has been obtained. This dependence is used for evaluation of the optimal surface density of CNTs in the array providing the maximum emission current density. The current-voltage characteristic of an array calculated with taking into account the statistical spread of the orientation angle of CNTs is compared with that obtained recently with taking into account a spread in geometrical parameters of CNTs.