Emission of Linearly Polarized Single Photons from Quantum Dots Contained in Nonpolar, Semipolar, and Polar Sections of Pencil-Like InGaN/GaN Nanowires

TL;DR

This paper demonstrates that pencil-like InGaN/GaN nanowires can host all three types of single photon emitters in different crystal regions, with properties influenced by the host crystal, advancing quantum light device integration.

Contribution

It introduces a novel nanostructure capable of hosting nonpolar, semipolar, and polar quantum dots for single photon emission, a first in the field.

Findings

All three quantum dot types emit single photons with narrow lines and high polarization.

Emission wavelength and lifetime depend on the crystal region, with subnanosecond lifetimes in some cases.

Localization sites are likely caused by indium fluctuations in the nanoshell.

Abstract

A pencil-like morphology of homoepitaxially grown GaN nanowires is exploited for the fabrication of thin conformal intrawire InGaN nanoshells which host quantum dots in nonpolar, semipolar and polar crystal regions. All three quantum dot types exhibit single photon emission with narrow emission line widths and high degrees of linear optical polarization. The host crystal region strongly affects both single photon wavelength and emission lifetime, reaching subnanosecond time scales for the non- and semipolar quantum dots. Localization sites in the InGaN potential landscape, most likely induced by indium fluctuations across the InGaN nanoshell, are identified as the driving mechanism for the single photon emission. The hereby reported pencil-like InGaN nanoshell is the first single nanostructure able to host all three types of single photon sources and is, thus, a promising building block for tunable quantum light devices integrated into future photonic circuits.