SHALLOW ACCEPTOR RESONANT STATES IN SI AND GE

The resonant states of the shallow accepters in Si and Ge have been obtained within the effective-mass approximation. The full cubic symmetry of the light, heavy and the spin-orbit split-offband have been considered. The resonant states are connected to the split off-band, and their energies are shifted from hydrogenlike positions due to the effect of mixing with the upper bands. The oscillator strengths of the optical transitions from the ground to the odd parity resonant states have been calculated, and compared with experimental data for Si. For the case of Ge our results predict the existence of shallow hydrogenlike resonant states associated with the split-off band. The simple spherical model has been constructed for the estimation of resonant energy shifts and resonant widths, and results are presented for the states in the Si1-xGex system.