Cold linear cathodes with carbon nanotube emitters and their application in luminescent tubes

We introduce an efficient method of fabricating cold, linear cathodes with carbon nanotube (CNT) emitters. A nickel wire was painted first with silver paste, then with CNT paste. After sintering under nitrogen and activation by adhesive tape, the cathode wire provided a stable and homogeneous emission density of 200 mA cm −2 at 6.2 V µm −1 . As an application, luminescent tubes were constructed using this CNT wire as the cathode and a transparent CNT film as the anode. These cold cathodes can replace conventional hot cathodes, which are widely used in vacuum electronic devices. The novel two-layer structure can be applied to any substrate, and is simple and inexpensive to fabricate.