Vibronic Spectra and the Dynamic Jahn‐Teller Effect of Cubic ZnS:Cu²⁺

Abstract

Abstract Near infrared absorption and emission spectra due to the transitions 2 T 2 ↔ 2 E of the Cu 2+ ion in cubic ZnS have been measured at 4K. The distinct vibronic sidebands of the absorption spectrum exactly correspond to various critical point energies of TA, TO, and LO lattice modes, whereas the structure of the luminescence spectrum cannot be interpreted in terms of lattice phonon satellites. A dynamic Jahn‐Teller interaction in the 2 T 2 ground state being in the same order of magnitude as static lattice spin‐orbit splitting and phonon energy is shown to produce this deviation from the mirror symmetry. Weak and strong coupling approximations in the cluster limit have been extended to include vibronic states with up to six E‐modes.