Temperature dependence of emission and lifetime in Eu(3+)- and Dy(3+)-doped GdVO4

Eu(3+)- and Dy(3+)-doped GdVO(4) samples synthesized by a high-temperature solid-state method are investigated by fluorescence spectroscopy at 298-750 K. They demonstrate potential for development as thermographic phosphors because the experimental and theoretical temperature dependence of the intensity ratio of the two lines agrees well. Experimental lifetime measurements recorded at 10-750 K were fitted using three theoretical models: multiphonon relaxation, temperature quenching through the charge transfer (CT) region, and our modified CT model (TDCT), which considers the temperature dependence of CT energy. The TDCT model yields the best results with good agreement between experimental and fitted lifetime data.