Determination of exciton binding energy of AlGaAs/GaAs quantum well as a function of well width using photoluminescence and x-ray diffraction spectroscopy

Abstract

Exciton binding energies for the heavy hole and light hole excitons in GaAs/AlGaAs multiple quantum wells of varying well widths were determined. The well widths were measured to be 48.5 Å, 90 Å, and 125 Å based on the x-ray diffraction periodicity of the samples. From the location of the room temperature photoluminescence peaks and using the effective mass approximation method, the exciton binding energies were computed. The values of exciton binding energies obtained from the computation are 10 meV, 8.3 meV, 7.9 meV for well widths of 48.5 Å, 90 Å, and 125 Å respectively, for the heavy hole excitons. For light hole excitons, the computation gives 13.5 meV, 12.7 meV and 9.2 meV for well widths of 48.5 Å, 90 Å, and 125 Å, respectively.