Study on large current field-emission carbon nanotube cathode

A large current and a high emission current density from printed carbon nanotube (CNT) are reported. To enhance the field-emission current, a small number of metal nano-particles were added to the CNT paste. The metal nano-particles enhanced the emitters-substrate contact and improved the CNTs adhesion properties. A large current of 68.0 mA is obtained from a cathode area of 1.1 mm2, and the high emission current density is about 6.2 A/cm2. The CNT cathode is applied to field-emission vacuum device prototype successfully. Experiments show that current and current density can meet the requirements for large current field-emission electron devices.