Radial tunnel diodes based on InP/InGaAs core-shell nanowires

We report on the fabrication and characterization of radial tunnel diodes based on InP(n+)/InGaAs(p+) core-shell nanowires, where the effect of Zn-dopant precursor flow on the electrical properties of the devices is evaluated. Selective and local etching of the InGaAs shell is employed to access the nanowire core in the contact process. Devices with an n⁺-p doping profile show normal diode rectification, whereas n⁺-p⁺ junctions exhibit typical tunnel diode characteristics with peak-to-valley current ratios up to 14 at room temperature and 100 at 4.2 K. A maximum peak current density of 28 A/cm² and a reverse current density of 7.3 kA/cm² at V_SD = −0.5 V are extracted at room temperature after normalization with the effective junction area.