Near infrared absorption of Ni²⁺in ZnO and ZnS: dynamic Jahn-Teller effect in the³T₂state

The study of the optical absorption of Ni2+ in ZnO and cubic, hexagonal and 6H polytype ZnS with polarized light has yielded an identification of all the expected zero phonon lines of the 3T2 crystal field term. Static crystal field theory is inadequate to explain the observed splittings in ZnO, but this can be explained by the dynamic Jahn-Teller effect involving moderately strong electron-phonon coupling. Phonon sidebands observed in ZnS are interpreted on the basis of the one-phonon spectrum of ZnS.