Structural and optical properties of low-density and In-rich InAs∕GaAs quantum dots

Abstract

Self-assembled InAs∕GaAs quantum dots have been grown at very low InAs growth rate in order to form sparse and large quantum dots (QDs) emitting in the near infrared (1300–1400nm), for application as single-photon sources. The structural and optical properties of these QDs as a function of the growth rate were systematically investigated. The QDs grown at the lowest rate (∼10−3ML∕s) present a very low dot density (∼2×108dots∕cm2), high In content, and good size homogeneity. Photoluminescence and time-resolved photoluminescence measurements performed at different powers and temperatures provide information on their luminescence efficiency, and on the recombination processes occurring in the low-density QDs as compared to higher densities.