Exciton localization in ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As/GaAs quantum wells observed by temperature-modulated photoluminescence

Temperature-modulated photoluminescence is used to study the recombination processes in ${\mathrm{In}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As/GaAs single and multiple quantum wells between 8 and 70 K. The measured spectra correspond to the temperature derivative of the photoluminescence signal. We have compared the experimental data with calculations based on the temperature-dependent localized and delocalized exciton energy, density, and linewidth, and have found good agreement between theory and experiment. It is shown that temperature-modulated photoluminescence spectroscopy can be used to obtain the exciton binding and localization energies.