Optica Open
arXiv.svg (5.58 kB)

Highly uniform GaSb quantum dots with indirect-direct bandgap crossover at telecom range

Download (5.58 kB)
posted on 2023-01-11, 22:06 authored by Abhiroop Chellu, Joonas Hilska, Jussi-Pekka Penttinen, Teemu Hakkarainen
We demonstrate a new quantum-confined semiconductor material based on GaSb quantum dots (QDs) embedded in single-crystalline AlGaSb matrix by filling droplet-etched nanoholes. The droplet-mediated growth mechanism allows formation of low QD densities required for non-classical single-QD light sources. The photoluminescence (PL) experiments reveal that the GaSb QDs have an indirect-direct bandgap crossover at telecom wavelengths. This is due to the alignment of the {\Gamma} and L valleys in the conduction band as a result of quantum confinement controlled by dimensions of the nanostructure. We show that in the direct bandgap regime close to 1.5 um wavelength, the GaSb QDs have a type I band alignment and exhibit excitonic emission with narrow spectral lines and very low inhomogeneous broadening of PL emission owing to the high material quality and dimensional uniformity. These properties are extremely promising in terms of applications in infrared quantum optics and quantum photonic integration.



This arXiv metadata record was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv.

Usage metrics