Density evolution of InAs/GaAs QDs formed by stacked SML growth: experiment and theory

The density evolution of InAs/GaAs quantum dots (QDs) during stacked submonolayer (SML) growth is investigated. It is experimentally demonstrated that during the final InAs deposition cycle the 3D QD density smoothly evolves from 10 7 and 10 10 cm -2 , allowing for a control over a wide range including low densities. Furthermore, the results are theoretically analyzed and modeled considering the 3D formation energy of the QDs. The model fits the experimental data well, and a 3D saturation density of 4.1×10 10 cm -2 is extracted. The wide control of the 3D SML QD density reported in the present work is particularly useful for quantum information applications that require very low densities (<10 8 cm-2).