Single-electron tunneling in InP nanowires

TL;DR

This study demonstrates single-electron tunneling and energy quantization in InP nanowires, highlighting their potential for quantum electronic applications through fabrication and low-temperature electrical characterization.

Contribution

First demonstration of Coulomb blockade and energy quantization in vapor-liquid-solid grown InP nanowires with detailed electrical characterization.

Findings

Coulomb-blockade behavior observed with ~1 meV charging energy

Low contact resistance (~10 kOhm) achieved with Ti/Al electrodes

Energy quantization due to wire confinement demonstrated

Abstract

We report on the fabrication and electrical characterization of field-effect devices based on wire-shaped InP crystals grown from Au catalyst particles by a vapor-liquid-solid process. Our InP wires are n-type doped with diameters in the 40-55 nm range and lengths of several microns. After being deposited on an oxidized Si substrate, wires are contacted individually via e-beam fabricated Ti/Al electrodes. We obtain contact resistances as low as ~10 kOhm, with minor temperature dependence. The distance between the electrodes varies between 0.2 and 2 micron. The electron density in the wires is changed with a back gate. Low-temperature transport measurements show Coulomb-blockade behavior with single-electron charging energies of ~1 meV. We also demonstrate energy quantization resulting from the confinement in the wire.