We report the first investigation of compositional disorder in quantum dots with subnanometer precision. We have investigated the compositional profile of a single InGaAs/GaAs quantum dot, of nominal In content x = 0.5, by using energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and atomic force and scanning tunneling microscope (AFM-STM) topography. The compositional analysis at nanoscale reveals a number of unexpected features: (i) In enrichment of the centre of the dot (about 65% In content); (ii) In diffusion outside the dot contour; (iii) In depletion of the wetting layer in the surrounding of the dot.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physica Status Solidi (B) Basic Research|
|State||Published - Mar 1 2001|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics