Carbon nanowalls on graphite for cold cathode applications

We demonstrate for the first time high performance carbon nanowall coated graphite cold cathodes. These graphite cold cathodes are capable of emitting high electron current density under low DC electric fields at room temperature. Carbon nanowalls with nanometer scale sharp edges are grown on graphite plates by means of DC plasma enhanced chemical vapor deposition in a gas mixture of methane and hydrogen. High performance cold cathodes are evaluated by means of measuring the electron field emission current density versus applied electric field (J-E), and examining the nano-graphite structures by SEM and Raman spectroscopy. Graphite is light weight, of high electrical and thermal conductivities, and chemically inert. It is expected that high performance and low cost graphite cold cathodes will find a broad spectrum of scientific and practical applications. (C) 2009 Elsevier B.V. All rights reserved.