Overview
- Researchers used local droplet etching to form nanocavities in AlGaAs and filled them with an approximately 1 nm InGaAs layer, reducing strain and boosting optical quality.
- Measured radiative lifetimes were about 300 picoseconds, roughly three times shorter than comparable Stranski–Krastanov–grown InGaAs dots in the same spectral range.
- Microphotoluminescence showed an extremely low surface density of around 0.2–0.3 quantum dots per square micrometer, easing isolation of single emitters.
- By varying indium content, emission wavelengths were tuned between roughly 780 and 900 nanometers at cryogenic temperatures, a range favorable for AlGaAs integrated photonics.
- Fine-structure splitting values matched leading systems, supporting entangled-photon applications, and the work, published in Nano Letters, was supported by FAPESP.