Photoluminescence of InAs quantum dots embedded in AlGaAs/InGaAs quantum wells with strain reducing layer

• PL and its temperature dependence have been studied in InAs QDs embedded in QWs.
• QD structures with capping layers (Al0.1Ga0.75 In0.15As(#1) or GaAs(#2)) are investigated.
• Thermal annealing has shown that Ga/In/Al intermixing is more efficient in #1, than in #2.
• The #1 is characterized by better optical parameters due to smaller level of elastic strain in #1.

Photoluminescence (PL) of InAs quantum dots (QDs) embedded in the Al0.30Ga0.70As/In0.15Ga0.85As/InGaAlAs/GaAs quantum wells (QWs) have been investigated in the temperature range of 10–500 K for as grown samples and after thermal annealing at 640 °C or 710 °C for two hours. QD samples with the different InAlGaAs capping layers (GaAs or Al0.1Ga0.75 In0.15As) have been studied. The higher PL intensity and lower energy of ground state (GS) emission are detected in the structure with Al0.1Ga0.75 In0.15As layer. This QD structure in as grown state has smaller PL thermal decay in comparison with this parameter in the structure with GaAs layer. The variation of PL intensities and peak positions at annealing are more essential in the QD structure with Al0.1Ga0.75 In0.15As capping layer, apparently, due to more efficient Ga(Al)/In intermixing.