MAGNETOOPTICAL ABSORPTION-SPECTRUM OF D- ION IN GAAS-GA0.75AL0.25AS QUANTUM-WELL

The magneto-optical absorption spectrum of a D- ion in a GaAs-Ga0.75Al 0.25As quantum well is calculated. We used the variational method base d on a two orbital picture of a D- ion, in which each single electron orbital is represented by a linear combination of anisotropic Gaussian orbitals. The calculated magnetic field dependence of the binding ene rgy of a D- ion agrees semi-quantitatively with the experimental resul t. In a magnetic field perpendicular to the well interface, the energi es of the one-electron excited states of a D- ion are completely quant ized, and broadening is essential for the calculation of the line shap e of the magneto-optical absorption spectrum. We considered two types of broadening effect, lifetime broadening and inhomogeneous broadening . Only the lifetime broadening effect reproduces fairly well the obser ved line shape of the magneto photo-conductivity spectrum. The assumed value of the lifetime is consistent with the measured Hall mobility. The effects of correlation on the one electron excited states of a D- ion are also discussed.