RESONANT INTERBAND TUNNELING IN INAS/GASB/ALSB/INAS AND GASB/INAS/ALSB/GASB HETEROSTRUCTURES

Tunneling in InAs/GaSb/AlSb/InAs and GaSb/InAs/AlSb/GaSb structures has been observed for the first time and shown to offer large peak-to-valley ratios at higher peak current densities than previous double-barrier and single-barrier polytype interband tunneling results. Room-temperature peak-to-valley ratios as high as 20:1 were observed at peak current densities of 28 kA/cm2. The highest peak-to-valley ratio observed at 80 K was 80:1 at 1.2 kA/cm 2. The large peak-to-valley ratios are attributed to resonant interband tunneling with a confined state and band-gap blocking of nonresonant currents. The operation of these devices is similar to asymmetric double-barrier structures.