Investigation of rare earth ions in ZnSe

The electrical properties of rare earth ions (Er⁺³, Tm⁺³ and Eu²⁺) doped into ZnSe crystals have been investigated by observing their optical absorptions, luminescent spectra, their Zeeman effects and ESR. The rare earth ions in the crystal from some kinds of centers close coupled with codopants or lattice defects, and they have emitted strong luminescence of the rare earth ions in the set group of (Er³⁺, Cu), (Tm³⁺, Cu) and (Tm³⁺, Li). The electronic structures of the latter two sets are the same, and Tm³⁺ exists in a crystal field of cubic symmetry. Parameters of the crystal field have been determined to suit best to the spectra obtained. Magnetic field induced absorption was observed in the absorption lines of ZnSe: Er, P by the pulse magnetic field Zeeman effect. From the ESR results of Eu²⁺ ions in ZnSe, it has been made clear that Eu²⁺ ions also exist in the crystal field of cubic symmetry.