A thermionic emission transistor comprising: an emitter region formed with a semiconductor material having a first conductivity type and a high impurity concentration; a collector region formed with a semiconductor material having a first conductivity type and a high impurity concentration; a base region...http://www.google.com.au/patents/US4482910?utm_source=gb-gplus-sharePatent US4482910 - Heterojunction emitter transistor with saturation drift velocity gradient in base
