Luminescence of yttrium tantalate doubly activated with europium and terbium under x-ray and electron beam excitations

This paper reports the luminescence spectra of YTaO4 activated with rare-earth ions, such as Eu3+ and Tb3+. The effect of these rare-earth ions on the luminescence of yttrium tantalate phosphors is studied. The luminescent properties are studied under X-ray and electron beam excitations. It is found that, under these excitations, the emission centers of the rare-earth activators (Eu3+, Tb3+) efficiently contribute to the overall luminescence. Color cathodoluminescence images clearly show the dependence of chromaticity on the different activators. These rare-earth activated phosphors exhibiting various luminescence chromaticities are promising materials for optoelectronic applications and for X-ray intensifying screens in medical diagnosis, because they provide a broad variation of visible photoluminescence from blue to red.