Photoluminescence of Two-Dimensional Electron System in Modulation-Doped GaAs Quantum Well

Abstract

We have carried out the photoluminescence measurements of two-dimensional electron system (2DES) in modulation-doped GaAs quantum well. It was found that the H band caused by radiative recombination between 2DES and holes shows a high energy tail below 4.2 K. We explain that the tail originates in the apparent breaking of the momentum conservation law, and that its reason is the electron scattering by neutral donors with the Bohr radius of ~10 nm. The distance between the adjacent donors, 80nm, is obtained from the coupling of the Landau levels in the different 2DES's. Excitonic effect is suggested by nonlinear dependence of the peak energy of the H band on magnetic fields and the lineshape analysis of the H band.