New method to fabricate field-emission cathode of carbon nanotubes

This paper presents a novel method to fabricate the field-emission cathode of carbon nanotubes (CNTs) to improve the stability of field emission against ion bombardment. The traditional processing of powder metallurgy is used to fabricate carbon nanotube cathodes, which have stronger adhesion of CNTs to substrates. In this method, metal powder and carbon nanotubes are mixed, pressed and sintered to form a bulk material. The surface of the sintered sample is etched by acid to remove a thin surface layer of metal, thus the top of CNTs form the tips for field emission, and their roots are embedded into the metal to enhance the adhesion of CNTs. The cathode fabricated by this method has typical I–V curve and F–N curve, and demonstrates more stable field emission than that made through chemical vapor deposition (CVD).