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Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
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Excitonic complexes in GaN/(Al,Ga)N quantum dots.

D Elmaghraoui1, M Triki1, S Jaziri1,2

  • 1Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis, Campus Universitaire, 2092 El Manar, Tunisia.

Journal of Physics. Condensed Matter : an Institute of Physics Journal
|February 2, 2017
PubMed
Summary

This study theoretically investigates excitonic complexes in polar gallium nitride/aluminum gallium nitride quantum dots (QDs). Controlling QD size is key for producing entangled photon pairs by tuning exciton-biexciton energy separation.

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Area of Science:

  • Quantum Dot Physics
  • Semiconductor Nanostructures
  • Excitonic Complexes

Background:

  • Excitonic complexes in polar quantum dots (QDs) are crucial for optoelectronic applications.
  • Understanding their behavior is essential for designing advanced semiconductor devices.

Purpose of the Study:

  • To theoretically investigate excitonic complexes in polar GaN/(Al,Ga)N quantum dots.
  • To explore the influence of quantum dot size on binding energies and spectral shifts.
  • To identify optimal conditions for producing entangled photon pairs.

Main Methods:

  • Theoretical investigation using a sum rule to calculate biexciton binding energy.
  • Analysis of exciton, charged exciton, and biexciton energy shifts.
  • Comparison of theoretical predictions with experimental data from InAs/GaAs QDs.

Main Results:

  • Binding energies of excitonic complexes in GaN/AlN QDs strongly correlate with QD size.
  • Positively charged excitons are always blueshifted due to hole localization.
  • Negatively charged exciton and biexciton energies can exhibit blueshift or redshift depending on QD size.
  • Al0.5Ga0.5N barriers aid in clear identification of charged excitons in larger QDs.

Conclusions:

  • Excitonic complex trends in QDs are governed by a balance between charge separation and correlation effects.
  • Careful control of GaN/(Al,Ga)N QD size enables the production of entangled photon pairs.
  • Theoretical predictions for charged excitonic complexes are validated by experimental data.