Blue luminescence in the WO3P2O5ZnO glass system

Luminescence in WO3P2O5ZnO glasses was measured and its origin was investigated. With XRD measurements, the amorphous phase of the glasses was determined to exclude a crystalline-phase region as the source of luminescence. A blue emission by 320 nm excitation was observed, similar to that in ZnWO4 crystals. The decomposition of the emission spectra into three bands and the Stokes shift were close to the results for ZnWO4 crystals. The laser spectroscopy revealed decay behavior similar to that for ZnWO4 crystals. Raman spectroscopy on the glasses showed the presence of WO6 groups in the glass. We conclude that the origin of the luminescence of the glasses is the same as that of ZnWO4. The luminescence in the glass is an intrinsic feature of the WO6 group. It results from the electronic excitation of O(2p) to W(5d) energy levels and the following decay in the WO6 groups of the glass.

Highlight
► A few WO3P2O5ZnO glasses showed blue luminescence by UV irradiation.
► The emission spectra and the Stokes shift are close to the data for ZnWO4 crystals.
► Raman spectroscopy showed the presence of WO6 groups in the glass.
► We conclude the origin of the luminescence is the same as that of ZnWO4.