Resonant interband tunneling current in InAs/AlSb/GaSb/AlSb/InAs double barrier diodes

Abstract

We have investigated the resonant interband tunneling currents (IRIT) in InAs/AlSb/GaSb/AlSb/InAs double-barrier resonant interband tunneling diodes. We have prepared samples with various thicknesses of the GaSb well (Lw) ranging from 5 to 47 monolayers (ML) and various thicknesses of the AlSb barrier (Lb) ranging from 0 to 5 ML, and analyzed the dependence of IRIT on these thicknesses. As Lw increases, IRIT increases if Lw is smaller than a certain boundary value of Lw (Lwb), but IRIT decreases if Lw is larger than Lwb. We have found that this boundary value Lwb depends on Lb, that is, Lwb decreases from 23 to 10 ML when Lb changes from 0.5 to 5 ML. Furthermore, we have also found that, for constant Lw, IRIT increases as Lb increases to a certain boundary value of Lb, and IRIT decreases for further increase in Lb. These marked behaviors of Lwb and IRIT on Lb are characteristic of the type II material systems and cannot be explained by the conventional model applied to type I resonant tunneling diodes. To explain these characteristic behaviors, we propose a model where the resonance level in the valence band of the GaSb well moves up toward the valence-band edge with an increase in Lb.