Growth and transport properties of (Ga,Al)Sb barriers on InAs

We have investigated the transport properties of (Ga,Al)Sb–InAs heterostructures grown by molecular-beam epitaxy with the Al composition in the range of 0.3–0.5 where the alloy serves as a potential barrier for electrons in InAs. Field effect capacitors using a thick (Ga,Al)Sb barrier demonstrate the modulation of carrier densities in InAs by the application of an electric field. In the region of thin (Ga,Al)Sb, where tunneling becomes dominant, a novel negative resistance appears in InAs/(Ga,Al)Sb/InAs single-barrier structures due to the specific band alignment of this system. The results have been further elucidated under a magnetic field.