Diameter-Dependent Electronic Transport Properties of Au-Catalyst/Ge-Nanowire Schottky Diodes

TL;DR

This study investigates how the electronic transport properties of Au-catalyst/Ge-nanowire Schottky diodes depend on nanowire diameter, revealing a surface-recombination-driven increase in conductance as diameter decreases.

Contribution

It provides the first detailed analysis linking nanowire diameter to Schottky barrier transport mechanisms, emphasizing surface effects and recombination dynamics.

Findings

Conductance density increases as nanowire diameter decreases.

Recombination time scales linearly with diameter due to surface effects.

Depletion width and recombination dominate charge transport in these diodes.

Abstract

We present electronic transport measurements in individual Au-catalyst/Ge-nanowire interfaces demonstrating the presence of a Schottky barrier. Surprisingly, the small-bias conductance density increases with decreasing diameter. Theoretical calculations suggest that this effect arises because electron-hole recombination in the depletion region is the dominant charge transport mechanism, with a diameter dependence of both the depletion width and the electron-hole recombination time. The recombination time is dominated by surface contributions and depends linearly on the nanowire diameter.