Fullerene-coated field emitters activated by a potassium ion flux in high electric fields

Use of ion processing to improve the quality of fullerene-coated field emitters

“…It has been demonstrated [5,6] that fullerene coated tip emitters can be activated by a potassium ion flux. Specifically, it has been found that exposure of a fullerene coating to a flux of slow potassium ions (with an energy of 40-100 eV) lowers the work function owing to the formation of metallofullerenes such as endohedrals C 60 @K or exohedrals K@C 60 .…”

“…Ion activation makes it possible to considerably (almost twofold) reduce the operating voltage necessary for extracting the field emission current from a tip cathode. In essence, the authors of [5,6] have demonstrated for the first time the feasibility of improving the quality of fullerene coated emitters by ion beam processing. Studies on the influence of ion bombardment on the performance of such emitters have continued.…”

“…Specifically, it has been found that exposure of a fullerene coating to a flux of slow potassium ions (with an energy of 40-100 eV) lowers the work function owing to the formation of metallofullerenes such as endohedrals C 60 @K or exohedrals K@C 60 . Rapid one stage and longer term three stage techniques of ion activation have been developed [5,6]. Ion activation makes it possible to considerably (almost twofold) reduce the operating voltage necessary for extracting the field emission current from a tip cathode.…”

“…It is believed that specially coated carbon and carboniferous emitters are highly stable against gaseous media and ion bombardment in high voltage devices operating in technical vacuum (see, e.g., [1,2]). Fullerene coatings suitable for field emitter protection have been developed and studied in [3][4][5][6][7].…”

Carbon Nanotube Field Emitters

“…Let's note, that not only elongated carbon nanotubes, but also pyramids from fullerenes are used as cold cathodes. Formation and characteristics of fullerene coatings on the surface of tungsten tip field emitters and emitters with ribbed crystals formed on their surface are studied by group of Sominskii from St. Petersburg State Technical University (Russia) (Tumareva et al, 2002;Tumareva et al, 2008). Methods of creating microprotusions on the surface of the coatings that considerably enhance the electric field have been developed and tested.…”