PHONON BROADENING OF EXCITONS IN GAAS/ALXGA1-XAS QUANTUM-WELLS

We have made transmission and reflectivity measurements of the temperature-dependent exciton linewidths for high-quality GaAs/Al0.3Ga0.7As quantum wells with well widths ranging between 28 and 340 and also for bulk GaAs. The LO-phonon contributions to the linewidths are found to depend only weakly on the well width. Detailed microscopic calculations of the well-width dependence of these linewidths have been made and are shown to be in quantitative agreement with experiment. These calculations provide a physical explanation of the weak dependence of the linewidth on the well width. © 1995 The American Physical Society.