Semiconductor biased superlattice tunable electron interference filter/emitter

It is shown that a voltage-biased semiconductor superlattice structure can serve simultaneously as a tunable electron-wave interference filter and electron emitter. A systematic design procedure for selecting the quantum well and barrier widths to be alternately high and low electron refractive indices and a quarter (or a half) of an electron wavelength in thickness is developed. A practical narrow-band filter/emitter consisting of layers of Ga1−xAlxAs and designed to emit 0.20-eV electrons is presented and analyzed. Such a structure would serve well as a tunable hot-electron emitter in ballistic transistors, and in future guided electron-wave integrated circuits.