ABSTRACT
Such behaviour of complementary feature A is observed for the first time. Indeed for the case of empty n = 2 electronic sub-band the PL study has shown convincingly that the carrier concentration and the excitation density strongly influence the additional feature appearance, immediately below the n = 2 bare exciton, in the presence of hole localization. This particular feature has been addressed to the FES manifestation. At least the FES evolves in PL spectra under appropriate light illumination being absent at the lowest excitation density. The FES excitation density dependence cannot be addressed to the presence of inner electric field and has to be bounced back to the properties of 2DEG unexplored. The model of Fano resonance between the many-body excitations of Fermi sea and the discrete excitonic state of n = 2 conduction sub-band is also not very plausible for the explanation of both the excitation density and temperature dependences of the feature observed experimentally.
