| Résumé | Strain modulation of a semiconductor band gap spatially confines excitons in a near-surface GaAs/AlGaAs quantum well. We report photoluminescence (PL) results of quantum dot arrays fabricated using tungsten stressors. Excitons are confined in a 35 meV potential well under 100 nm dot stressors, which is 2.4 times deeper than that observed using 100 nm carbon stressors. Such a confinement potential corresponds to quantum dot energy level splittings of approximately 7 meV. Arrays of dots are studied, each with individual stressors of a different size ranging from 100 to 800 nm. The lateral potential well depth, as measured by the red shift in PL signal, is dependent on the stressor width and thickness in a well-understood manner. The integrated PL signal from the dots increases with increasing temperature, indicating increased efficiency of trapping of excitons from the quantum well into the quantum dots. Interpretation of excitation spectra, and observation of higher energy levels, are complicated by the details of the strain pattern and the near-field coupling of radiation between the metallic stressors and the quantum well. |
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