Photoluminescence of charged InAs self-assembled quantum dots

We have used capacitance and photoluminescence spectroscopy to study the optical properties of charged InAs self-assembled quantum dots. When the dots are loaded with electrons, the ground-state transition in the photoluminescence spectra shows a redshift of about 15 meV accompanied by a decrease in intensity and a broadening. In addition, an excited-state transition appears. All the observations mentioned above are attributed to many-body effects caused by charging of the quantum dots with electrons. The observed changes of the photoluminescence signal are also discussed in terms of field effects.