Photoluminescence of biased GaAs/AlxGa1−xAs double quantum wells — many-body effects

Photoluminescence (PL) spectra of an MBE-grown symmetric View the MathML source wide double quantum well located in the intrinsic region of a p–i–n diode were investigated in electric and magnetic fields. In addition to the commonly reported spatially direct (DX) and indirect transitions, we observed in the spectra a new PL band, placed independently of the applied electric field View the MathML source below the DX peak. Furthermore, we observed a slight shift of the DX transition to lower energies in a strong inversion accompanied by a simultaneous transfer of its intensity to a new band emerging View the MathML source below the DX energy. The new PL bands were interpreted as a recombination of DX excitons, coupled by Coulomb interaction to 2D degenerate electron or hole gases in the adjacent well.