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

Abstract

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 In 0.15Ga 0.8As layers, using variable pumping power (P) in the range 10–1000 W/cm 2 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.