METASTABLE ONE-ELECTRON AND 2-ELECTRON DONOR STATES IN GAAS AND CDF2

The strongly localized one-electron (D-0) and two-electron (D-) donor states are considered with the lattice deformation around tile donor c enter taken into account. For GaAs, the donor energy levels have been calculated as functions of the hydrostatic pressure. Tile calculated e nergy positions and pressure coefficients agree with the experimental data. It is shown that the interaction with phonons reduces the probab ility of radiative transitions between tile states of different locali zation and leads to the metastability of shallow-level donor states wi th respect to the D- state in GaAs and both the states (D-0 and D-) in CdF2.