Morphology and Composition of InAs/GaAs Quantum Dots

Abstract

Surface compositional maps of self-organized InAs/GaAs quantum dots were obtained with laterally resolved photoemission spectroscopy. We found a surface In concentration of about 0.85 at the center of the islands which decreases to 0.75 on the wetting layer. Comparison with concentration values found in the core of similar dots suggests a strong In segregation on the topmost surface layers of the dots and on the surrounding wetting layer. Furthermore, the morphological properties of the dots such as size and density have been measured with plan-view transmission electron microscopy and low energy electron microscopy.

Surface compositional mapping of self-assembled InAs/GaAs quantum rings

“…1(b) shows an XPEEM chemical map of the In concentration x of the same surface region, obtained with the procedure of Refs. [20,23]. The area above the WL appears as a rather grainy region with an average x$0.52.…”

Compositional mapping of semiconductor quantum dots and rings

“…Laterally resolved photoemission spectroscopy was also applied to the study of InAs quantum dots grown by MBE on GaAs(001) substrates (growth temperature 540°C, growth rate 0.03 ML/s) [45,131,132]. Surface compositional maps were Fig.…”