Indium segregation and enrichment in coherent InxGa1-xAs/GaAs quantum dots

Significant differences in the image features of InxGa1-xAs quantum dots (Q Ds) grown on (001) and vicinal (001) GaAs were seen in [001] on-zone bright -held transmission electron microscope images. Simulated images were obtain ed by modeling the strain field distribution of the QDs with finite element analysis and then using this model in dynamical electron diffraction contr ast simulations. Comparison of the experimental images and the simulated im ages shows that (i) In segregation exists in the QDs and (ii) the average I n content of the QDs is higher than the average In content of the film.