Carbon Nanotube Field Emission Technology For Vacuum Electronic Device Applications

Carbon nanotube (CNT) is a relatively new carbon allotrope discovered in 1991 by Iijima et al. A CNT is a honeycomb lattice rolled into a cylinder. In 1995, four years after the discovery of CNT, field emission from CNTs was reported by three groups at low operating temperature, low-turn-on fields, and high current densities. From 1998 onward, the perspective to use CNTs in field emission devices such as field emission display, x-ray source, and microwave source spurred on efforts worldwide. In this chapter, we briefly review the recent development of carbon nanotube field emission technology for future vacuum electronic device applications in medical x-ray imaging and radiotherapy, high-power microwave and flat-panel displays.