Temperature dependence of exciton linewidths in InSb quantum wells

We studied the linewidths of excitons in InSb/Al0.09In0.91Sb quantum wells between 4.2 and 300 K using Fourier-transform infrared spectroscopy. Even though the exciton binding energy is only about 1 meV, the absorption is excitonic up to room temperature, due to very weak LO-phonon-electron coupling. The electron-phonon coupling constants and exciton binding energies were obtained through fitting the experimental data. We found that acoustic phonon scattering must be taken into account in fitting the experimental exciton linewidths.