Structural study of InGaAs/GaAs quantum dots grown by metalorganic chemical vapor deposition for optoelectronic applications at 1.3 μm

We have studied the influence of difference growth conditions on the two-dimensional to three-dimensional growth mode transition for a specific class of InGaAs/GaAs quantum dots ~QDs! optimized for applications to optical devices operating around 1.3 mm ~In content x'0.5). The dots are grown by low-pressure metalorganic chemical vapor deposition on GaAs substrates. We demonstrate that the critical layer thickness corresponding to optimized single-QD layer structures ~i.e., with reduced wetting layer thickness and high uniformity! can be controlled by kinetic effects. The optimized growth conditions allow us to grow six-layers stacked QD structures as active material for the fabrication of a light emitting devices operating around 1.3 mm at room temperature.