The present invention relates to the production of highly efficient films for field-effect
electron emitters, wherein said films may be used in the production of flat displays, in electronic microscopes, in
microwave electronics, in light sources as well as in various other applications. This invention more precisely relates to a
cold cathode that comprises a substrate having a
carbon film applied thereto. The
carbon film has an irregular structure consisting of carbon micro-ridges and / or micro-threads which are perpendicular to the surface of the substrate, have a size
ranging typically from 0.01 to 1 microns and a distribution density of between 0.1 and 10 mum2. This invention also relates to method for producing a cold
electrode, wherein said method comprises generating a
DC current discharge in a mixture comprising
hydrogen and a carbon-containing additive, and further depositing the carbon phase on the substrate located at the
anode. This method is characterized in that the
discharge is generated at a
current density of between 0.15 and 0.5 A / cm2. The
deposition process is carried out in a mixture containing
hydrogen and vapors of ethylic
alcohol or
methane, under an overall pressure of between 50 and 300 Torrs and at a substrate temperature of between 600 and 900° C. The concentration of ethylic
alcohol vapors ranges from 5 to 10% while that of
methane vapors ranges from 15 to 30%. This invention also relates to another method for producing a
cold cathode, wherein said method comprises generating a
microwave discharge at an
absorbed power of between 100 and 1000 W. This discharge is generated in a mixture containing gaseous
carbon oxide as well as
methane in an 0.8-1.2 concentration and under a pressure of between 10 and 200 Torrs, the carbon phase being further deposited on the substrate. This method is characterized in that the
deposition process is carried out at a temperature on the
substrate surface that ranges from 500 to 700° C.