InAs self-assembled quantum dots are grown in the vicinity of a two-dimensional electron gas. Transport experiments show a progressive reduction of the electron mobility with increasing dot density, which indicates the influence of the quantum dots on the electrical properties of the electron gas. A saturation of the mobility is observed for the highest dot density samples. Transmission electron microscopy studies confirm the existence of the dots and reveal the formation of a vertically aligned double dot. Calculations of scattering times due to repulsive potentials are in agreement with the experimental data and suggest that the self-assembled quantum dots act as controllable scattering centers that can be used to tailor the electron gas properties.

• Received 4 February 1998

DOI:https://doi.org/10.1103/PhysRevB.58.1506