The crystal-field theory of 3d impurity ions is extended to the case of strongly covalent semiconductors. Analytical expressions are obtained for the crystal-field splitting, spin-orbit splitting and Racah parameters with the inclusion of covalent effects. The Koopmans theorem for the impurity d states is shown to be invalid in strongly covalent crystals. The connection is established between the one-electron language of the band theory of deep levels and the many-electron classification of intracentre spectroscopy.
|Number of pages||17|
|Journal||Journal of Physics C: Solid State Physics|
|State||Published - 1984|