Doping incorporation paths in catalyst-free Be-doped GaAs nanowires

TL;DR

This study investigates how beryllium dopes GaAs nanowires during growth, revealing preferential facet incorporation and diffusion paths, which advances controlled doping techniques for nanowire-based device fabrication.

Contribution

It uncovers the specific incorporation paths of Be in GaAs nanowires, highlighting the dominant facet incorporation and diffusion mechanisms, aiding in precise doping control.

Findings

Be incorporates mainly via nanowire side facets

Diffusion of Be into the nanowire volume occurs

Facet incorporation is the primary doping pathway

Abstract

The incorporation paths of Be in GaAs nanowires grown by the Ga-assisted method in molecular beam epitaxy has been investigated by electrical measurements of nanowires with different doping profiles. We find that Be atoms incorporate preferentially via the nanowire side facets, while the incorporation path through the Ga droplet is negligible. We also demonstrate that Be can diffuse into the volume of the nanowire giving an alternative incorporation path. This work is an important step towards controlled doping of nanowires and will serve as a help for designing future devices based on nanowires.