10 September 2014 Type-I InAs quantum dots covered by GaAsSb strain reducing layer
Author Affiliations +
This work is focused on examining ultrafast photoluminescent properties of InAs quantum dots (QDs) grown on GaAs substrate and covered by GaAs1-xSbx strain reducing capping layer (SRL). The samples were prepared by Stranski-Krastanow growth method. The aim is to understand the processes occurring inside the QDs and wetting layer (WL) and how the SRL influences the energy levels inside the QDs. It was already proven that the SRL of this composition can decrease energies of transitions inside these QDs to the IR range, which makes these structures promising candidate for devices emitting near infrared radiation. It is possible to shift the luminescence wavelength towards 1.3 and even 1.55 μm, which are widely used in telecommunications. Using upconversion method we measured luminescence dynamics of two samples with different concentration of Sb in the SRL with sub-picosecond time resolution. We investigated the effect of temperature, as well as the intensity and wavelength of the excitation pulse. We also compared the properties of the samples after excitation by λ=760 nm pulse and 850 nm pulse – the former one is energetically above the GaAs substrate band gap; in the second case we excited only the QDs and the WL. We consequently derived recombination and relaxation processes occurring inside InAs QDs and also proved that the transport of charge carriers from the substrate and from the WL into the QDs is efficient.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Martin Pokorný, Martin Pokorný, Martin Kozák, Martin Kozák, František Trojánek, František Trojánek, Jiří Pangrác, Jiří Pangrác, Alice Hospodková, Alice Hospodková, "Type-I InAs quantum dots covered by GaAsSb strain reducing layer", Proc. SPIE 9161, Nanophotonic Materials XI, 916113 (10 September 2014); doi: 10.1117/12.2061749; https://doi.org/10.1117/12.2061749


Quantum dots for single and entangled photon emitters
Proceedings of SPIE (February 23 2010)
Single-photon-emitting diode
Proceedings of SPIE (December 08 2002)
The role of Sb compositions on the properties of InAs...
Proceedings of SPIE (February 20 2012)

Back to Top