We have demonstrated tunable bistability and a strong negative differential resistance in InAs/GaSb core–shell nanowire devices embedding a radial broken–gap heterojunction. Nanostructures have been grown using a catalyst-free synthesis on a Si substrate. Current–voltage characteristics display a top peak–to–valley ratio of 4.8 at 4.2 K and 2.2 at room temperature. The Esaki effect can be modulated – or even completely quenched – by field effect, by controlling the band bending profile along the azimuthal angle of the radial heterostructure. Hysteretic behavior is also observed in the presence of a suitable resistive load. Our results indicate that high–quality broken–gap devices can be obtained using Au–free growth.
Contact person: Mirko Rocci, NANO Pisa