Time-resolved spectroscopy of InAs quantum dots using one-side modulation-doping technique: renormalization and screening

We present the optical properties of modulation-doped InAs/GaAs quantum dots (QDs). Bandgap renormalization is clearly observed from a red shift of the emission peaks on the QDs with various modulation-doping concentrations, demonstrating that exchange interactions of electrons within single states have no effect on renormalization. Screening due to the electrons at modulation-doped layer as well as the photo-generated carriers in GaAs matrix plays an important role in reducing the radiative recombination rate.