Cathodoluminescence wavelength imaging study of clustering in InAs/GaAs self-assembled quantum dots

D. H. Rich, C. Zhang, I. Mukhametzhanov, A. Madhukar

Research output: Contribution to journalArticlepeer-review


Cathodoluminescence wavelength imaging (CLWI) of InAs/GaAs self-assembled quantum dots (SAQDs) was performed to study the spatial variation in the spectral lineshape of the broadened quantum dot (QD) ensemble. The lineshape 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. SAQDs were also prepared by punctuated island growth (PIG), in which deposition of the total desired amount is broken into two or more stages each separated by time delays. CLWI reveals a reduced variation in the energy of the dominant CL emission on a ∼μm spatial scale, correlating with a narrower size distribution of larger QDs for PIG, as measured in atomic force microscopy.

Original languageEnglish
Pages (from-to)173-178
Number of pages6
JournalMaterials Research Society Symposium - Proceedings
StatePublished - 1 Jan 2000
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science (all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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