Photoluminescence spectrum dependences on temperature and excitation power in InAs quantum dots embedded in InGaAs/GaAs quantum wells

The photoluminescence (PL), its temperature and excitation power dependences have been studied in the symmetric In0.15Ga1-0.15As/GaAs quantum wells (QWs) with embedded InAs quantum dots (QDs), obtained with the variation of the QD growth temperature (470-535°C). The increase of QD growth temperatures is accompanied by the enlargement of the QD lateral sizes (from 12 up to 28 nm) and by the shift non monotonously of the PL peak positions. The fitting procedure has been applied for the analysis of the temperature dependences of PL peaks. The obtained fitting parameters testify that in studied QD structures the process of In/Ga inter diffusion between QDs and capping/buffer layers takes place. The intensity of the In/Ga inter diffusion depends on the density and the size of QDs in studied QD structures. Additionally the In/Ga intermixing influent essentially on the dependence of the integrated PL intensity versus excitation power.