Luminescence of a dense two-dimensional electron gasinvolving free- and bound holes in theGaAs/InGaAs/AlGaAs quantum well

摘要

The photoluminescence (PL) from a pseudomorphicmodulation-doped GaAs/InGaAs/AlGaAs quantum well (QW) with ahigh density of the two-dimensional electron gas (1.6×1012 cm?2 ) at lowtemperature and high magnetic field is examined. Two distinct cut-offenergies at the high-energy side of the spectrum are observed. These areattributed to the optical recombination of electrons from the vicinity ofFermi level with the free- or bound holes in the QW. It is found that thetotal integrated intensity of the PL, as well as the PL intensity in the lowenergyPL tail have pronounced minima at even Landau-level fillingfactors. This is explained as an effect of oscillations of screening by a 2Delectron gas in magnetic field.