The covalence effect of energy levels of ZnS:Mn2+

The contribution of the different covalence for t2 and e orbitals must be considered in the investigation of the optical and magnetic properties of the transition metal ion in II-VI and III-V semiconductors. In present paper, two covalent parameters Nt and Ne associated with t2 and e orbitals have been adopted to describe the covalence. The energy matrices considering the different covalence for t2 and e orbitals have been provided for d5 ions in crystal. These matrices show that the contribution from the Racah parameter A cannot be neglected in calculation of energy-level of d5 ions in covalent crystal. The calculated results using the matrix show that the energy levels of E4 and A14 states split, and the energy-level difference between E4 and A14 states increases with increase of the different covalence between t2 and e orbitals. These energy levels are always degenerate, when the different covalence for t2 and e orbitals is neglected. By using the energy matrices, the energy-level of ZnS:Mn2+ has been calculated. The calculated energy levels of ZnS:Mn2+ are in good agreement with the experiments.