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Quantum efficiency and oscillator strength of InGaAs quantum dots for single-photon sources emitting in the telecommunication O-band

Große, Jan; Mrowiński, Paweł; Srocka, Nicole; Reitzenstein, Stephan

We demonstrate experimental results based on time-resolved photoluminescence spectroscopy to determine the oscillator strength and the internal quantum efficiency (IQE) of InGaAs quantum dots (QDs). Using a strain-reducing layer, these QDs can be employed for the manufacturing of single-photon sources emitting in the telecom O-Band. The oscillator strength and IQE are evaluated by determining the radiative and non-radiative decay rates under the variation of the optical density of states at the position of the QD for InGaAs QDs emitting at wavelengths below 1 μm. For this purpose, we perform measurements on a QD sample for different thicknesses of the capping layer realized by a controlled wet-chemical etching process. From numeric modeling of the radiative and non-radiative decay rates dependence on the capping layer thickness, we determine an oscillator strength of 24.6 ± 3.2 and a high IQE of (85 ± 10)% for the long-wavelength InGaAs QDs.
Published in: Applied Physics Letters, 10.1063/5.0059458, American Institute of Physics (AIP)
  • This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 119, 061103 (2021) and may be found at https://doi.org/10.1063/5.0059458.