Optical spectroscopy of a single Al0.36In0.64As/Al0.33Ga0.67As quantum dot

We report results of interband spectroscopy of a single Al_0.36In_0.64As/Al_0.33Ga_0.67As self-assembled quantum dot. The single dot spectroscopy has been carried out at low temperature as a function of the excitation power and magnetic field up to 8 T. The emission spectra as a function of excitation power show two distinct groups of transitions that we associate with the recombination from ground and excited quantum dot levels with a spacing of ~70 meV. The application of magnetic field allows us to identify the exciton emission as well as the emission from the biexciton, and charged exciton complexes with binding energies of ~5 meV. The binding energies compare favorably with results of calculations.