FERMI-EDGE SINGULARITY IN LUMINESCENCE SPECTRA OF P-TYPE MODULATION-DOPED ALGAAS GAAS QUANTUM-WELLS/

We have studied an enhancement of the oscillator strength for optical transitions near the Fermi energy in p-type modulation-doped quantum w ells, which, so far, deserved much less attention than analogous n-typ e systems, because of the complicated valence band structure involved. The relatively wide (L = 150 Angstrom) quantum wells and high doping levels were used, containing more than one occupied subband. The enhan cement in the photoluminescence intensity at the Fermi energy resulted from the strong correlation and multiple scattering of holes near the Fermi edge by the localized electrons. PACS numbers: 42.55.Pr, 73.20. Dr.