Sequential directional deposition of one-sided (In,Ga)N shells on GaN nanowires by molecular beam epitaxy

TL;DR

This paper introduces a novel sequential directional deposition method for growing homogeneous (In,Ga)N shells on GaN nanowires using molecular beam epitaxy, enabling controlled shell growth on specific nanowire facets.

Contribution

It presents a new technique for directional shell growth on nanowires, allowing for selective and homogeneous coating with potential for tailored nanostructures.

Findings

Homogeneous (In,Ga)N shells can be grown on single facets of GaN nanowires.

Higher In content induces strain and nanowire bending.

In incorporation and emission spectra depend on growth temperature and flux ratio.

Abstract

Capitalizing on the directed nature of the atomic fluxes in molecular beam epitaxy, we propose and demonstrate the sequential directional deposition of lateral (In,Ga)N shells on GaN nanowires. In this approach, a sub-monolayer thickness of each constituent atomic species, i.e. Ga, In, and N, is deposited subsequently from the same direction by rotating the sample and operating the shutters accordingly. Using multiple iterations of this process, we achieve the growth of homogeneous shells on a single side facet of the nanowires. For higher In content and thus lattice mismatch, we observe a strain-induced bending of the nanowire heterostructures. The incorporation of In and the resulting emission spectra are systematically investigated as a function of both the growth temperature and the In/Ga flux ratio.