The effect of powder preparation processes on the luminescent properties of yttrium oxide based phosphor materials

Eu and Tb³⁺ doped Y₂O₃, Y₂SiO₅ and Y₃Al₅O₁₂(YAG) phosphor materials were prepared by different routes to investigate their effect on luminescent characteristics in micron and submicron particle size powders. Both amorphous low temperature co-precipitate reacted and crystalline high temperature solid state reacted (reference) powders were further crystallized in steam(S) and fluoriferous steam (SF) atmospheres at 1000 \ ̀ghC for 8 hours, respectively. In spite of sharp XRD peaks in S, SF treated samples, all SEM images exhibited "soft" aggregates of about 3 μm in average diameter consisting of 0.2-0.3 μm small particles. The powder samples characterized by XRD, SEM and luminescence spectra indicated that low temperature reacted samples which were further crystallized in steam or fluoriferous steam have greater improvements in the luminescent intensity than solid state reacted Y₂O₃, Y₂SiO₅ based phosphors after S, SF treatments.