Abstract
We use cross-sectional scanning tunneling microscopy to examine the shape and composition distribution of quantum dots (QDs) formed by capping heteroepitaxial islands. The QDs have a truncated pyramid shape. The composition appears highly nonuniform, with an In-rich core having an inverted-triangle shape. Thus the electronic properties will be drastically altered, relative to the uniform composition generally assumed in device modeling. Theoretical analysis of the QD growth suggests a simple explanation for the unexpected shape of the In-rich core.
- Received 12 July 1999
DOI:https://doi.org/10.1103/PhysRevLett.84.334
©2000 American Physical Society