Photoluminescence inhomogeneity and InAs QD laser structure parameters

The photoluminescence (PL) and its power dependences have been studied in InAs quantum dots (QDs) embedded in the symmetric In0.15Ga0.85As/GaAs quantum wells (QWs) with different PL intensities and different shapes of PL spectra. It was shown that two reasons are responsible for the PL intensity inhomogeneity and different shapes of PL spectra in the studied structure. The first reason deals with the variation of QD concentrations and the second one related to the bimodal QD size distribution in DWELL. At the same time both types of QD ensembles are characterized by high QD quality.