Modified self-assembly of InAs islands acting as stressors for strain-induced InGaAs(P)/InP quantum dots

We report modified self-assembly of InAs islands. acting as stressors for strain-induced InGaAs(P) quantum dots (SIQDs). The quantum dots are fabricated by growing InAs islands on top of a neat-surface InGaAs(P)/InP quantum well (QW). The compressively strained QW affects the size and density of the InAs islands, as compared to islands grown on a plain InP buffer. By adjusting the growth conditions, the height of the InAs stressors is tuned from 15 to 30 nm while the areal density varies around 10(9) cm(-2). The confinement of carriers in the SIQDs is characterized by low-temperature photoluminescence. Increasing the size of the InAs stressor is shown to enhance the depth of the lateral confinement potential and reduce the level splitting of excited QD states. However, the small inhomogeneous broadening of the SIQD transitions, as narrow as 11 meV, shows no correlation with the height dispersion of the stressor islands.