“Double-high” field electron emission of screen-printed carbon nanotube cathodes

Abstract

High performance cold cathodes based on carbon nanotubes (CNTs) are fabricated by using a screen-printing method. The CNT cathode shows stable electron emission with no significant deterioration and the temperature-dependent emission has been also investigated. The results demonstrate that the maximum emission current of CNT emitters can be reached to 16.9 mA at electric field of 7.6 V μm−1, corresponding to super-high current density of 562 mA cm−2 under continuous driving mode. Under pulse driving mode, the peak current of 70 mA with a high current density of 2333 mA cm−2 is further obtained at electric field of 11.5 V μm−1. The presented CNT emitters display high electron emission both in total current and current density under continuous and pulse driving modes. This work will open a new avenue towards designing “double-high” CNT cold electron sources for broad application prospects in vacuum electronic devices requiring high current and density simultaneously.