Phonon scattering in novel superlattice-asymmetric double barrier resonant tunneling structure

Abstract

The scattering effects (specifically LO-phonon scattering) in a 45 Å AlAs/80 Å GaAs/33 Å AlAs asymmetric double barrier resonant tunneling (ADBRT) structure with a short period GaAS/Al0.3Ga0.7As superlattice incorporated on one side of the double barrier have been studied and characterized. Enhanced levels of current conduction were produced in the ADBRT due to the superlattice miniband electron transport under forward bias. And the effect of the said superlattice on the phonon scattering phenomena exhibited by the entire device was subsequently examined. Magnetic field fan diagrams at 4.2 K under reverse bias showed a new feature at an energy of 22 meV that could be explained on the basis of previously unreported GaAs LO-phonon scattering processes from the first excited emitter level. Finally, quenching of phonon-assisted tunneling in reverse bias on decreasing the period of the superlattice was also observed.