Well size related limitations on maximum electroabsorption in GaAs/AlGaAs multiple quantum well structures

Experimentally determined maximum electroabsorption in GaAs/Al0.33Ga0.67As multiple quantum wells over the quantum well width range of 17–260 Å is related to the confinement of the electronic wave functions in the quantum well, increasing with enhanced confinement. However, for very narrow wells, this increase in maximum electroabsorption is diminished by strong broadening of the excitonic resonances due to phonon scattering, eventually leading to a peak value of 22 200 cm−1 at a 35 Å well width.