Photoluminescence line-shape analysis in quantum wells embedded in superlattices

The temperature evolution of the main photoluminescence (PL) mechanisms, in GaAs quantum wells embedded in short-period AlAs/GaAs superlattices, is in vestigated. PL spectra are measured from 2 to 300 K. A detailed line-shape analysis of the PL peaks is performed by means of a statistical model, incl uding both free exciton and free carrier recombination. The Fits based on t his model reproduce satisfactorily the experimental PL line shapes and allo w to assess quantitatively the relative contributions of free excitons and free carriers to the radiative recombination at different temperatures. The results indicate the predominant role of free excitons in the radiative re combination up to room temperature, and are consistent with the mass action law. (C) 2001 Elsevier Science B.V. All rights reserved.