On the Photoionization of Deep Repulsive Impurity Centres in Semiconductors

The photoionization spectrum is calculated for impurity centres having a repulsive Coulomb potential a t large distances. The short range potential is well approximated by a delta‐function. Effects of the electron‐phonon coupling are taken into account both to the acoustical and optical modes. Transitions to a higher lying band are considered. The results are in satisfactory agreement with the observed spectral dependence.