Since Auger-stimulated intraband recombination is expected to produce emission spectra similar to those of pure intraband processes, we also simulated the expected PL spectra for intraband recombination as a cross-check. In the calculation for intraband recombination, the JDOS in Equation 1 can roughly be approximated as constant over the range of energies discussed here, and consequently has no influence on the recombination. This means only f e and f h determine the spectral evolution of the recombination process. The form of the non-equilibrium electron and hole distributions under cw-excitation has been extensively discussed in literature by several groups. The simulated I/I 425 spectra (Figure ) reproduce the general behavior of the experimental spectra (Figure ) surprisingly well. In particular, the flat behavior and the gradual decrease for higher wavelengths are accurately described. The broadband emission originates from the broad non-equilibrium charge distribution above and below E F while the gradual decrease towards lower wavelengths reflects its cut-off of the electron distribution at the excitation energy (Figure ). The lower the excitation energy, the further the cut-off shifts to higher wavelengths. We achieved the best agreement between experiment and data for ζ = 1 × 10 -2 and resulting values for δ E (ω ex ) between 2 × 10 -3 and 10 -2 . This population inversion is considerably larger than the inversion estimated for direct intraband excitation of around δ E ≈ 10 -3 -10 -9 as predicted by Dubi & Sivan 70 for a 2.6× lower excitation intensity. We assume that the differences between simulation and measurement, in particular on the long-wavelength side, could be reconciled by including the band structure in the simulation. In summary, we conclude that the observed PL was most certainly a result of intraband recombination.