Observation of resonant tunneling in InSb/AlInSb double-barrier structures

We report the first observation of resonant tunneling in the InSb/AlxIn1−xSb material system. Five samples with InSb quantum well thicknesses ranging from 70 to 110 Å and Al0.5In0.5Sb barrier thicknesses ranging from 22 to 36 Å were grown by molecular beam epitaxy on GaAs(100) substrates at a temperature of 420 °C. The best sample, which had 22-Å-thick barriers and a 110-Å-thick quantum well, displayed a peak-to-valley current ratio of 1.4(3.9) at room temperature (77 K) with a corresponding peak current density of 3.6×104 A/cm2. Transmission electron microscopy revealed threading dislocations, misfit dislocations, and microtwins in the barrier region.