Abstract
Low-temperature photoluminescence was studied in a large number of pseudomorphic modulation-doped transistor structures having an As (x<0.3) quantum well with sheet densities up to 2.5× . The Fermi edge appears clearly in the spectra, and its separation from the n=1 transition peak varies linearly with measured sheet densities of the two-dimensional electron gas. Appearance of a strong high-energy peak marks the occupation of the second electron subband if the electron density or well width is large, and a feature due to phonon interactions is present if the Fermi energy exceeds the optical-phonon energy. No enhancement is seen at the Fermi edge except for a slight increase when it lies less than about 10 meV below the second subband.
- Received 23 February 1989
DOI:https://doi.org/10.1103/PhysRevB.39.8033
©1989 American Physical Society