PHOTOLUMINESCENCE WITH MODERATE EXCITATION AND RESONANT RAMAN-SCATTERING IN GAAS ALGAAS SUPERLATTICES/

Additional peaks in the photoluminescence spectra of GaAs/AlGaAs super lattices at energies above the position of the quasi-two-dimensional e xciton peak were recorded under moderate levels of excitation. These p eaks were attributed to the contribution of transitions between higher (n less than or equal to 3) subbands on the basis of envelope calcula tions of the structure of the subbands and transition matrix elements, as well as on the basis of resonant Raman scattering data. The depend ences of the energies of these transitions, the populations of the cor responding subbands, and the localization of the electronic wave funct ion on the thickness of the barrier layers were investigated. The X-Ga mma transport of electrons in real space was detected in structures wi th thick AlGaAs barrier layers. (C) 1996 American Institute of Physics .