Abstract

Starting from fundamental principles, quantitative analogies between quantum electron waves in semiconductors and electromagnetic optical waves in dielectrics have been developed.¹ Due to those analogies optical design techniques can be adapted for the design of narrowband superlattice electron filter/emitters. A voltage-biased semiconductor superlattice structure can serve simultaneously as an electron filter and as a continuously tunable emitter. The thickness of each superlattice layer is restricted to be an integer multiple of the monolayer thickness. Furthermore, for practical materials (Ga_1−xAl_xAs), there is a usable composition range and a range of usable electron energies to avoid intervalley and phonon scattering that degrade the electron coherence. Under these constraints, an optimum design procedure has been developed that specifies the layer compositions and thicknesses for a given bias voltage and input kinetic energy. Examples of Ga_1−xAl_xAs filter/emitters are presented. Sensitivity of the device to fabrication variations is investigated. These superlattice electron filter/emitters can exhibit very narrow electron kinetic energy passbands and can be integrated into solid state devices for potential use as monoenergetic emitters for electroluminescent devices, photodetectors, and fast ballistic transistors.

© 1989 Optical Society of America