We report the temperature dependence and polarization properties of the zero-phonon lines and broad band emission of the 4T2 → 4A2 emission of Cr3+ ions substituting for Zn2+ ions in ZnWO4. The zero-field splitting of the 4T2 state is calculated and compared to the separation of the zero-phonon lines associated with this broad emission band. A molecular orbital (MO) method is used to calculate the polarization properties of the emission. Comparison with experiment suggests that T2u odd-parity distortion and odd-mode vibrations are most effective in inducing the broad band transition.
- polarized photoluminescence
- broad bandwidth