Temperature Dependence of Photoluminescence from Epitaxial InGaAs/GaAs Quantum Dots with High Lateral Aspect Ratio
A. Musiała, G. Sęka, A. Maryńskia, P. Podemskia, J. Misiewicza, A. Löfflerb, S. Höflingb, S. Reitzensteinb, J.P. Reithmaierb, c and A. Forchelb

aInstitute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
bTechnische Physik, University of Würzburg and Wilhelm-Conrad-Röntgen-Research Center for Complex, Material Systems (RCCM), Am Hubland, D-97074 Würzburg, Germany
ccurrently at: Institute of Nanostructure Technologies and Analytics, Technische Physik, Universität Kassel, Germany
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Hereby, we present a study of a thermal quenching of emission from self-assembled epitaxial highly asymmetric quantum dots in InGaAs/GaAs material system for both ensemble and single dot regime. Pronounced interplay between the intensity of wetting layer and quantum dots originated emission was observed as the temperature was increased, evidencing a thermally activated energy transfer between the two parts of the system and an important role of the wetting layer in determining the optical properties of these anisotropic nanostructures. The carrier activation energies have been derived and possible carrier loss mechanisms have been analyzed. Single dot study revealed activation energies slightly varying from dot to dot due to size and shape distribution. The problem of the shape uniformity of individual quantum dot has also been addressed and possibility of additional carrier localization within the investigated structures has been found to be insignificant based on the recorded spectroscopic data.
DOI: 10.12693/APhysPolA.120.883
PACS numbers: 78.67.Hc, 65.80.-g