Uniform Electron Field Emission from a Carbon-nanotube-based Cold Cathode with Micro-imprinted Microstructures

Abstract

Carbon nanotube (CNT) is an excellent field while for microwave devices a much larger current density emitter due to its small diameter (1-40 nm), high aspect ratio (> lA/cm2) is preferred.(>103), and high theoretical current limit (-1jA / SWNT). Methods for assembling and integrating SWNTs orThe applications like CNT-FED or 11PM require uniform MWNTs onto a device surface to form a cathode include distribution of field emission current, low turn-on field, and high current density. However, macroscopic cathodes made plasma enhanced chemical vapor deposition (PECVD) [4], from CNTs for CNT-FED and microwave devices have been p shown to exhibit low emission site density (103-104 sites/cm2) water assisted CVD [5], electrophoresis deposition [6], compared to CNT density (109-101o /cm2 ), non-uniformity in spray coating of CNT mixture [7], and screen printing from emission sites distribution, and lower current density a paste mixture of CNTs [8]. Thermal CVD or PECVD achievable than dispenser cathode. The non-uniformity of can grow CNTs directly inside a 30 ,um hole, but the emission sites distribution is closely related to field screening length and uniformity across a panel size area is difficult to effect at individual sites. Only the CNTs with the highest achieve. Screen printing is a cost effective method, but the local electric field can emit current. The effect of field resolution of an ordinary screen is usually larger than 200,um enhancement factor, which is a strong function of local microstructure and a result of manufacture method, is found and