Phonon Sideband of Quasi-Two-Dimensional Excitons in GaAs Quantum Wells.

We present an investigation of the absorption edge in quasi- two-dimensional GaAs quantum well heterostructures. We find that the exciton-longitudinal optic phonon interaction plays an important role in determining the spectral characteristics and magnitude of the low temperature absorption. A calculation of the absorption coefficient based on the two-dimensional Frohlich interaction shows excellent agreement with the data.