To provide a cold cathode that has large current emission performance and stability.
The cold cathode electron emitter comprises a wide band gap (WBG) semiconductor that is n+ doped in high concentration, p doped WBG region, and a metallic layer having a low work function. A different configuration of this structure includes a region that is p+ doped in high concentration between the p region and the metallic layer. By these structures, large current can be emitted with stable (durable) operation. The reason why large current density is realized is that the p doped region and the p+ doped region work as a material of negative electron affinity when they contact the metal of low work function. The injecting emitter that has n+-p-M and n+-p-p+-M structures uses relatively low electric field and is not affected by the contamination and/or absorption of the accelerated ion, and therefore is stable.
BRATKOVSKI ALEXANDRE M
BIRECKI HENRYK
