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Characteristics of carbon‐fibre cold field emission tips with a dielectric coating

Field electron emitters have been prepared by coating a carbon fibre with an epoxylite resin, and their properties investigated. The emission stability is improved compared with an uncoated fibre. An optimum coating thickness of 0.2–0.3 µm has been found. Energy spectra have been measured and peak shifts of up to 1 eV as a function of emission current have been observed. Surprisingly, these peaks shifts are comparable with those found for uncoated carbon fibres and for resin‐coated tungsten emitters. Their origin is not clear, but it seems that resistive drop cannot be the whole explanation. We speculate that these peak shifts may be related to the dynamics of surface‐state occupation at the material/vacuum interface. Copyright © 2004 John Wiley & Sons, Ltd.