Optical absorption by an exciton bound to an ionized donor impurity in anisotropic semiconductors

Abstract
The oscillator strength is determined for the dipole absorption of the anisotropic exciton—ionized donor complex, taking into account the electronic structure and using our previously obtained anisotropic envelope wave function. It is shown that the anisotropy of the electron lowers markedly the oscillator strength, whereas the hole anisotropy does not give any significant effect. In the case of CdS, the results improve previous variational calculations made in the isotropic case.