INJECTION COLD EMITTER WITH NEGATIVE ELECTRON AFFINITY BASED ON WIDE-GAP SEMICONDUCTOR STRUCTURE WITH CONTROLLING BASE

摘要

A cold electron emitter may include a heavily n+ doped wide band gap (WBG) substrate, a p-doped WBG region, and a low work function metallic layer (n+-p-M structure). A modification of this structure includes heavily p+ doped region between p region and M metallic layer (n+-p-p+-M structure). These structures make it possible to combine high current emission with stable (durable) operation. The high current density is possible because the p-doped (or p+ heavily doped) WBG region acts as a negative electron affinity material when in contact with low work function metals. The injection emitters with the n+-p-M and n+-p-p+-M structures are stable since the emitters make use of relatively low extracting electric field and are not affected by contamination and/or absorption from accelerated ions. In addition, the structures may be fabricated with current state-of-the-art technology.