High emission current density from printed CNTs by enhanced emitters-substrate contact

The carbon nanotube is a promising electron source due to its excellent field emission performance. However, the large emission current from a carbon nanotube cathode is limited with the increased emission areas. In the article, a high emission current density from printed carbon nanotubes is reported. To enhance the field emission current, a little amount of metal nano-particles was added to the CNTs paste. The metal nano-particles enhanced the emitters-substrate contact, and improved CNT´s adhesion properties. A large current as 33.9 mA is obtained from a cathode area of 0.8 mm², and the high emission current density is about 4.2 A/cm². This current density can meet large current field emission electron devices requirements.