Analytic modelling of the thin-film field-emission triode

An analytic model for the thin-film field-emission triode has been develope d which allows fast and accurate calculation of the electric field distribu tion on the surface of the thin-film cathode for a wide range of device dim ensions and operating voltages. The model can also be used to calculate the potential distribution throughout the device. The model is used together w ith the Fowler-Nordheim equation and with the published field-emission data on a carbon nanotube film to calculate the profiles of emission current al ong the surface of the thin-film cathode for a number of geometries. Non-un iform emission is shown to be a problem, which will result in undesirably l arge gate currents. Increasing the anode voltage to bias the cathode to jus t below its emission threshold even when the gate is off is shown to be an effective means of providing uniform emission when the gate is turned on wh ile preserving a sufficiently high on/off ratio of emitted current. (C) 200 1 Elsevier Science Ltd. All rights reserved.