Photoluminescence in GaAs/AlGaAs quantum wells associated with excited confinement subbands

We report on photoluminescence emission features which are observed from GaAs/AlGaAs multiple quantum wells only at elevated temperatures (T>10K), using weak cw laser excitation. These features have energies higher than those of the heavy and light hole excitons and are associated with interband transitions between excited confinement conduction and valence subbands. Their energies are compared with values calculated from measured well dimensions and accepted band parameters for a series of samples with well widths between 80 and 375Å. © 1986.