Cathodoluminescence wavelength imaging of InAs/GaAs self-assembled quantum dots (SAQDs) was performed to study the spatial variation in the spectral line shape of the broadened quantum dot (QD) ensemble. The line shape was found to vary on a scale of ∼μm, revealing attendant variations in the size distribution of SAQD clusters on this spatial scale. Energy variations in clusters of SAQDs are found to exhibit a spatial correlation with the efficiency of luminescence and the activation energy for thermal re-emission of carriers. A reduction in the energy variation of the QD clusters occurs when the thickness of the spacer layers in vertically self-organized samples is reduced or the number of stacks is increased.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)