Self-organization of (In,Ga)As/GaAs quantum dots on relaxed (In,Ga)As films

We report the synthesis of (In,Ga)As/GaAs quantum dots on strain-relaxed (In,Ga)As epitaxial films. It is found that the incorporation of a relaxed prelayer provides a systematic and effective method for controlling the dot distribution and emission wavelength. The robustness of the optical properties of quantum dots to dislocations may provide a method for engineering the band structure of quantum dot devices. We demonstrate, for example, that longer band-to-band emission wavelengths can be obtained by simply decreasing the residual strain in the relaxed films.