Optical properties of InAlAs quantum dots in an AlGaAs matrix

Structural and optical properties of InxAl1−xAs quantum dots (QD) embedded in an Al0.30Ga0.70As matrix are studied as a function of InAs mole fraction (x). Decreasing of x results in a sequential disappearance of bound electron and hole states in the QDs. There is a range of indium compositions were photoluminescence is determined by type-II optical transitions between electrons localized in a Al0.3Ga0.7As layer and holes localized in the QDs.