Analysis of the excitation and emission spectra of tungstates and molybdate

The excitation and emission spectra of CaWO4, MgWO4, PbWO4, ZnWO4, and CaMoO4 were analyzed by a configurational coordination model. The spectral line shapes simulated by a configurational coordination model with a singlet ground state and an excited triplet state well explained the line shape of the luminescence spectra and the line shape at the rising part of the excitation spectra of these salts at room temperature. The energy level of the excited triplet state and the reorganization energies at the ground sate and the triplet state were determined. It was concluded that the potential curve at the excited state becomes shallower than that at the ground state for these systems.