M. Kemerink et al., MANY-PARTICLE EFFECTS IN BE-DELTA-DOPED GAAS ALXGA1-XAS QUANTUM-WELLS/, Physical review. B, Condensed matter, 58(3), 1998, pp. 1424-1435
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].