Determination of the subband carrier densities in a strained GaAs/In0.15Ga0.85As/Al0.22Ga0.78As single quantum well using photoluminescence

Photoluminescence (PL) measurements on a strained GaAs/In0.15Ga0.85As/Al0.22Ga0.78As single quantum well grown by molecular beam epitaxy were performed to determine the subband carrier densities in the In0.15Ga0.85As single quantum well. The PL results obtained from the samples with two populated electron subbands were dominated by two spectral bands. The electronic subband energies and the Fermi energy in the In0.15Ga0.85As quantum well were calculated by a self-consistent method taking into account exchange-correlation effects together with strain and nonparabolicity effects. The subband carrier densities determined using the PL spectrum were in good agreement with those obtained from self-consistent calculation results and Shubnikov-de Haas measurements. These results clearly demonstrate the feasibility of using PL measurements, which involve no sample destruction, to determine subband carrier densities.