Synthesis and characterization of Y₂O₃:Pr³⁺ phosphor powders by simple solvent evaporation

The synthesis of trivalent praseodymium doped yttrium oxide powders (Y₂O₃:Pr³⁺) by the solvent evaporation method as well as their structural and luminescent (cathodoluminescence and photoluminescence) properties are reported as a function of the concentration of the reagents and annealing temperatures in the 400 to 1100 °C range. These powders become polycrystalline in a cubic Y₂O₃ structure at temperatures above 600 °C. An increase in the diffraction peaks intensity was observed as the temperature is increased. Transmission electron microscopy analysis showed irregular needle like crystallites and the characteristic electron diffraction rings for polycrystalline powders on samples annealing above 600 °C. Scanning electron microscopy showed that these crystallites clump into larger particles of irregular shape. Luminescence spectra show the characteristic peaks at 620 and 630 nm due to ¹D₂ to ³H₄ transitions in Pr³⁺ ions in the Y₂O₃ host.