Effects of a thin InGaAs layer on carrier dynamics of InAs quantum dots

Carrier dynamics of self-assembled InAs quantum dots (QDs) have been investigated by introducing a thin In0.32 Ga0.68 As layer between InAs QD layer and InAlGaAs layer, which was lattice-matched to an InP substrates. With increasing thickness of In0.32 Ga0.68 As layer the photoluminescence (PL) emission of the InAs QDs is red-shifted and the PL decay time increases due to increase in QD size and improved QD shape and density. It is found that increases in QD size and/or density lead to a corresponding increase in the PL decay time.