a field emission device includes a substrate in which a well has been formed . carbon fibers with a high aspect ratio are deposited within the well , wherein the well is sufficiently deep so that axes of a large number of the carbon fibers are substantially coaxial with a long axis of the well . a conductive anode is positioned relative to the substrate so that an electric potential applied between the conductive anode and the substrate causes an emission of electrons from the carbon fibers towards the conductive anode .