Synthesis of Y₂O₃:Eu phosphor with various particles morphologies by solvothermal reaction in methanol-water system

A methanolwater mixed solvent was used as a reaction medium for the synthesis of Eu³⁺-doped Y₂O₃ (Y ₂O₃:Eu) phosphor. Y₂O₃:Eu was prepared under solvothermal conditions at 150300° C for 324 h using a solution of water and methanol as the reaction medium followed by heat treatment at 1000°C for 2 h. The phase composition and optical properties of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectroscopy. The powders obtained were composed of plate-like particles, spindle-like particles, and whisker particles and were different for samples prepared under supercritical, subcritical, and normal conditions of methanol. With the reaction temperature increasing, the particle size became smaller, in particular, the particles were ̃500nm in size at 300°C under supercritical condition of methanol. After calcination at 1000°C for 2 h, the obtained powders retained the initial shape. The emission peaks of the fluorescence were assigned to the f-f transitions of the Eu³⁺ and exhibited red emission. The fluorescence intensities and internal quantum efficiency exhibited various values dependence on the morphology of the obtained particles.