Metamorphic InAs quantum dots: Photoluminescence features related to cooperative phenomena in the quantum dot-matrix system

The photoluminescence (PL) characteristics have been studied in two series of nanostructures comprising metamorphic InAs quantum dots (QDs) in In x Ga 1− x As matrices of variable composition ( x = 0.14–0.30) with and without 5-nm-thick inserts of In 0.4 Ga 0.6 As or In 0.4 Al 0.6 As solid solutions. It is established that cooperative phenomena, which take place in the QD-matrix system with inserts when the indium arsenide content in the matrix exceeds 20% ( x > 0.20), proceed according to different mechanisms depending on the insert composition. These phenomena substantially change the PL peak position and intensity and are more important than the size and homogeneity of the initially introduced QDs as factors determining the optical properties of the nanostructures under consideration.