Probing the excitonic states of site-controlled GaN nanowire quantum dots

Quantum dots synthesis within ternary III-V nanowire towards light emitters in quantum photonic circuits: a review

The positioning of quantum dots (QDs) in nanowires (NWs) on-axis has emerged as a controllable method of QD fabrication that has given rise to structures with exciting potential in novel applications in the field of Si photonics. In particular, III-V NWQDs attract a great deal of interest owing to their vibrant optical properties, high carrier mobility, facilitation in integration with Si and bandgap tunability, which render them highly versatile. Moreover, unlike Stranski-Krastanov or self-assembled QDs, this configuration allows for deterministic position and size of the dots, enhancing the sample uniformity and enabling beneficial functions. Among these functions, single photon emission has presented significant interest due to its key role in quantum information processing. This has led to efforts for the integration of ternary III-V NWQD non-classical light emitters on-chip, which is promising for the commercial expansion of quantum photonic circuits. In the current review, we will describe the recent progress in the synthesis of ternary III-V NWQDs, including the growth methods and the material platforms in the available literature. Furthermore, we will present the results related to single photon emission and the integration of III-V NWQDs as single photon sources in quantum photonic circuits, highlighting their promising potential in quantum information processing. Our work demonstrates the up-to-date landscape in this field of research and pronounces the importance of ternary III-V NWQDs in quantum information and optoelectronic applications.

Linearly polarized photoluminescence of InGaN quantum disks embedded in GaN nanorods

We have investigated the emission from InGaN/GaN quantum disks grown on the tip of GaN nanorods. The emission at 3.21 eV from the InGaN quantum disk doesn’t show a Stark shift, and it is linearly polarized when excited perpendicular to the growth direction. The degree of linear polarization is about 39.3% due to the anisotropy of the nanostructures. In order to characterize a single nanostructure, the quantum disks were dispersed on a SiO₂ substrate patterned with a metal reference grid. By rotating the excitation polarization angle from parallel to perpendicular relative to the nanorods, the variation of overall PL for the 3.21 eV peak was recorded and it clearly showed the degree of linear polarization (DLP) of 51.5%.