Intrinsic current bistability in InAs/AlxGa1−xSb resonant tunneling devices

We report the design and demonstration of a novel resonant tunneling device displaying bistability in operating current over a range of applied voltage. The device is based on a type II InAs/AlxGa1−xSb (0.4<x<0.6) double barrier heterostructure. This structure permits the simultaneous accumulation of electrons and holes in the quantum well/barrier region, resulting in a dependence of the steady-state charge distribution on the bias history of the device. This dependence is experimentally manifested as an ‘‘S’’-shaped negative differential resistance region under current-controlled measurement conditions or as hysteretic I-V behavior under voltage-controlled conditions. Room temperature operating currents in excess of 2.5×105 A/cm2 are observed, along with peak-to-valley voltage ratios up to 1.5.