Reflectance of two-dimensional excitons in GaAs-AlGaAs quantum wells

Abstract

We report reflectance, excitation, and luminescence spectra of GaAs-AlGaAs quantum wells in the energy region of the light- and heavy-hole exciton transitions. The properties of the two-dimensional exciton are analyzed by using a dielectric model. The excellent agreement between experimental and theoretical reflectance spectra leads to an accurate determination of the excitonic eigenenergies, oscillator strength, and damping. The energy positions of the emission peaks of the excitation spectra are close to the eigenenergy as determined from reflectance, whereas the emission maxima of the luminescence spectra exhibit red shifts depending on the excitation intensity.