INTERBAND TUNNELING IN INAS/GASB/ALSB HETEROSTRUCTURES

We report the experimental observation of negative differential resistance (NDR) at room temperature from a structure consisting of a single InAs(n)/GaSb(p) interface. The peak current densities ranged from 4.2 x 10(4) to 8.0 x 10(4) A/cm2 depending on how the structure is doped. The mechanism that causes the NDR is similar to that of an Esaki tunnel diode. We have also observed NDR at room temperature in a second class of novel devices. These structures consist of a thin layer of AlSb displaced from a single InAs(n)/GaSb(p) interface. NDR with peak current densities greater than 1.6 x 10(5) A/cm2 is seen in these structures. We attribute the increase in peak current densities with the addition of the AlSb barrier to the formation of a quasi-bound state between the AlSb layer and the InAs/GaSb interface. This quasi-bound state forms either in the conduction band of InAs or the valence band of GaSb, depending on where the AlSb barrier is placed and leads to a resonate enhancement of the current in the structures.