MANY-PARTICLE EFFECTS IN BE-DELTA-DOPED GAAS ALXGA1-XAS QUANTUM-WELLS/

We have performed photoluminescence (PL) and photoluminescence excitat ion measurements on two series of center-delta-doped p-type GaAs/AlxGa 1-xAs quantum wells, with variable well width and doping concentration . The experimental data are compared with self-consistent field calcul ations. The effects of exchange and correlation were found to be extre mely important and various models for the hole exchange and correlatio n are compared with the experimental data. It is found that the model recently proposed by Bobbert et al. [P. A. Bobbert rt al., Phys. Rev. B 56, 3664 (1997)] consistently describes our experimental observation s. Furthermore, for well widths w greater than or equal to 600 Angstro m clear excitonic effects were observed, for hole densities as high as 12 X 10(12) cm(-2), which is explained in terms of small spatial over lap between the screening particles and the exciton along the growth d irection. In contrast to earlier work on similar samples, we found no indication for a Fermi-edge singularity in the PL spectra of our sampl es. Peaked structures at the high-energy side of the PL spectra are sh own to arise from bulk transitions. [S0163-1829(98)04324-0].