Monolithic axial InGaAs quantum dot emitters in GaAs-based nanowires via Sb-mediated facet engineering

TL;DR

This paper demonstrates a method to create high-quality InGaAs quantum dots in GaAs nanowires using Sb-mediated facet engineering, enabling efficient single-photon emission for quantum photonics.

Contribution

It introduces a novel facet engineering technique with Sb incorporation to suppress twins and achieve abrupt axial quantum dots in nanowires.

Findings

Enhanced probability of forming thin, abrupt quantum dots at nanowire tips.

Single-photon emission confirmed by antibunching with g^{(2)}(0)<0.4.

Short emission lifetimes of around 0.51 ns indicating efficient emitters.

Abstract

GaAs-based nanowires hosting active quantum heterostructures provide a promising route toward monolithic integration of single-photon sources on silicon, a key requirement for scalable quantum photonics. However, ultrathin axial quantum-emitter formation is often hindered by facet-dependent growth dynamics and rotational twins, which induce lateral overgrowth and compromise interface abruptness. Here, we develop InGaAs-based quantum emitters by tailoring facet evolution via dilute Sb incorporation, which efficiently suppresses twins and promotes confined axial insertion at the growth-front facet. This approach significantly enhances the probability of obtaining abrupt, few-nanometer-thin quantum dots at the nanowire tip. Single-nanowire optical spectroscopy reveals intense, spatially localized emission from the active region with lifetimes as short as (0.51 $\pm$ 0.02) ns, and second-order photon-correlation measurements consistently exhibit pronounced antibunching with $g^{(2)}(0)<0.4$, confirming single-photon emission. These results establish a strong correlation between twin density and axial heterostructure formation, identifying defect control as a key factor in realizing monolithically integrated nanowire single-photon sources.