Recent years the intensive researches of the cold electron emitters based on carbon materials take place. The reason for these is a dramatically low value of the threshold field of vacuum electron emission in carbon nanotubes, diamond and diamond-like films. This fact determines the possibility of applying them in flat electro luminescence displays and light sources. The main problem of the flat field emitters is non-uniformity of the emission current due to the random distribution of "emitting sites" - points of high emission current density. As a solution of this problem we propose to use the detonation - synthesised nanodiamond (ND) as the base of field electron emitter. According to the results of our recent works this material consists of perfect crystalline diamond clusters with extremely narrow size distribution 45 ± 3 angstroms. Each diamond nanocrystal has a conductive onion-like shell of sp2 - bonded carbon.

The structure of ND based flat field emitter consist of amount of separate clusters placed on fine surface of carbide forming metal (nickel, wolfram). Such structure allows each cluster on the surface to be the emitting site. We developed the technique for emitter structure preparation by electrophoresis in non-conductive solvent. For separation of clusters, the high-intensive ultrasound treatment was used. To control the conductance of cluster shell we used high temperature annealing of the prepared structures.

The program "Low dimensional quantum structures" of the Russian Academy of Sciences supported this work.