Strong blue shift of the luminescence of indirect AlAs/GaAlAs quantum wells with excitation intensity

A strong blue shift (up to 40 meV) with increasing laser power is observed in the luminescence from the transition between the conduction subband at the X minimum in AlAs and the valence subband at Γ maximum in GaAlAs. This shift is explained by the band bending due to the spatial separation of the photoexcited electrons and holes. The observed energy shift with laser power is related to the calculated shift with excited carrier density and, in this way, the excess carrier lifetime is determined. © 1990.