Multiple excited state modification in InAs/InGaAs quantum dot structures at high excitation power

This paper presents the investigation of photoluminescence (PL), connected with ground (GS) and four excited states (1-4-ES) in highly uniform self-assembled InAs quantum dots (QDs) embedded into the In0.15Ga0.8As layers, using variable pumping power (P) in the range 10-1000 W/cm2 at the temperature 12 K. The peak positions of GS and ES emission bands depend on an excitation light power. The energy differences between GS and 1-4ES optical transitions are not equidistant and equal to 48.8, 46.5, 40.3 and 33.4 meV, respectively, at highest power level. It was shown that many-particle effects in such high populated QDs is essential and the exchange/correlation and direct Coulomb contributions do not vanish in the investigated strong confined QDs.