In the paper, comparative studies of near-IR photoluminescence (PL) in structures with GaAs/AlGaAs quantum wells possessing different selective doping profiles have been performed. The PL spectra recorded at 5 K for different intensities of interband optical pumping were analyzed and main channels of radiative recombination were determined. The dependences of the main PL line intensities on the pump level were obtained. The results of the studies performed suggest that n-GaAs/AlGaAs nanostructures with the compensating acceptor impurity located not in the n-GaAs quantum well, but in its barriers, are preferable for terahertz radiation generation.