Abstract

Starting from fundamental principles, the quantitative analogies between electron waves in semiconductors and electromagnetic waves in dielectrics have been developed.¹ A voltage-biased semiconductor superlattice structure that can serve simultaneously as an electron filter and a tunable emitter has recently been proposed.² The current-voltage (I–V) and transmission characteristics of these structures are analyzed by means of a nonself-consistent (NSC) and a self-consistent (SC) calculation. For the NSC calculation, only the Schrodinger equation is solved, but for the SC calculation both the Schrodinger and Poisson equations are solved iteratively.³ The approach of Esaki et al⁴. is used for the computation of the I–V characteristics. It is shown that for low-to-medium Fermi energies, the effect of the space-charge on the filter/emitteroperation is small and results in a shift of the I–V and transmission characteristics toward higher bias voltages. Examples of Ga_1-xAl_xAs filter/emitters are presented. Resonant filter/emitters with a current peak-to-valley ratio of ~50, as well as nonresonant devices, are analyzed. Charge-density distributions are presented. Superlattice electron filters/emitters can be used as high-speed switches and oscillators and as monoenergetic emitters in electroluminescent devices and photodetectors.

© 1990 Optical Society of America