Highly uniform GaSb quantum dots with indirect-direct bandgap crossover at telecom range
Chellu, Abhiroop; Hilska, Joonas; Penttinen, Jussi-Pekka; Hakkarainen, Teemu (2021-05)
Chellu, Abhiroop
Hilska, Joonas
Penttinen, Jussi-Pekka
Hakkarainen, Teemu
05 / 2021
051116
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202106216001
https://urn.fi/URN:NBN:fi:tuni-202106216001
Kuvaus
Peer reviewed
Tiivistelmä
We demonstrate a new quantum-confined semiconductor material based on GaSb quantum dots (QDs) embedded in a 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 Γ and L valleys in the conduction band as a result of the quantum confinement controlled by the dimensions of the nanostructure. We show that in the direct bandgap regime close to 1.5 μm 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.
Kokoelmat
- TUNICRIS-julkaisut [19214]