Phase space filling and band gap renormalization in the luminescence of highly excited InGaAs/GaAs quantum wires

The influence of many-body effects in one-dimensional (1D) electron-hole (e-h) plasmas on the multi-subband emission of InGaAs/GaAs modulated-barrier quantum well wires (qww's) is investigated. A detailed modelling of the measured photoluminescence (PL) for various excitation intensities permits a clear demonstration of several many-body effects in the spectra. In particular, we observe a transition of an exciton to a plasma emission, and the saturation of the plasma emission of different lateral subband transitions due to band filling. The analysis yields a significant band gap renormalization. The observed red-shifts particularly of the low-energy wings of the spectra are explained in terms of an incomplete compensation between the band edge shifts and the excitonic correlations in these 1D structures.