Resumo: InAs/GaAs submonolayer quantum dots rely on the vertical alignment of two-dimensional InAs islands separated by thin GaAs layers. These stacks arise from the local strain field generated by the lattice mismatch between the constituent materials. However, experimental observations show that such quantum dots appear irregular and shorter than expected. Indium segregation is particularly strong in the InAs/GaAs system and is suspected to weaken the internal strain field. To confirm this assumption, we simulated the strain in the GaAs matrix surrounding InAs inclusions with the shape of either a full sphere or a thin truncated hemisphere. The results demonstrate that, when the original two-dimensional InAs islands are realistically represented by a thin truncated hemisphere subjected to strong In segregation, the internal strain is indeed much lower than that required to form full stacks, even for distances as short as a few monolayers between inclusions.

Weakening of the internal strain field in InAs/GaAs submonolayer quantum dots due to indium segregation

Cantalice, T.F., Urahata, S.M. and Quivy, A.A.

Micro and Nanostructures, 212, 208567 (2026).

DOI : 10.1016/j.micrna.2026.208567