FERMI-ENERGY-EDGE SINGULARITY IN QUANTUM-WELLS CONTAINING MORE THAN ONE OCCUPIED SUBBAND

[摘要] A study of the Fermi-energy-edge singularity in asymmetric modulation-doped quantum wells is reported. It is shown that high densities of free carriers in filled n = 1 electron subbands have no significant influence on the edge singularity in partly occupied n = 2 subbands, demonstrating the weakness of intersubband Coulomb-scattering processes. The enhancement of oscillator strength at the Fermi energy is of very similar magnitude to that for excitonic transitions in undoped quantum wells.

[关键词] LUMINESCENCE SPECTRA;OPTICAL-SPECTRA;ABSORPTION;PHOTOLUMINESCENCE;HETEROSTRUCTURES;CARRIER