Semiconductor Biased Superlattice Tunable Interference Filter/emitter

Abstract

Continuously tunable, biased, semiconductor superlattice electron interference filter/emitter which can serve, for example, as a hot electron emitter in a ballistic transistor, provides energy selectivity for substantially ballistic electron wave propagation at electron energies above the superlattice potential barriers. The layers of the biased superlattice have alternatively high and low electron refractive indices wherein each layer is a quarter or half of an electron wavelength in thickness and wherein the quantum well barrier widths are adjusted in the direction of emission to provide the desired energy selectivity.