Relationship Between Photoluminescence Spectra and Low-Field ElectricalProperties of Modulation-Doped AlGaAs/GaAs Quantum Wells

摘要

We describe the influence of sheet charge density and crystalline quality on thephotoluminescence (PL) spectra of AlGaAs/GaAs n-type modulation doped quantum wells (MDQWs). We discuss the various contributions to the PL linewidth at 4.2 K. The linewidth at 77 K is approximately equal to the Fermi energy, and is independent of crystalline quality, making it a good measure of sheet carrier density. At 4.2 K, the crystalline quality also influences the PL linewidths; however, the carrier density can be deduced from the high-energy cutoff point of the PL spectra. The ratio of 77 K to 4.2 K linewidths correlates fairly well with the crystalline quality, as measured by the 77 K Hall mobility.