Hydrothermal synthesis of Y₂O₃:Eu³⁺ nanorods and its growth mechanism and luminescence properties

Homogeneous Y₂O₃:Eu³⁺ nanorods with the lengths of several micrometres were successfully synthesised on a large scale by using a urea-assisted hydrothermal method and a post-calcining process. In this study, the influences of urea content and NaOH concentration on the oriented growth, photoluminescence (PL) and electroluminescence (EL) intensity enhancement of Y₂O₃:Eu³⁺ were investigated. As a precipitant for isotropic growth, urea can counteract the effect of NaOH on oriented growth along the c-axis during hydrothermal treatment. The Y₂O₃:Eu³⁺ powders exhibited a strong red emission centred at 613 nm under either 245 nm UV excitation or the direct current high electric field. The PL intensity of the Y₂O₃:Eu³⁺ phosphor prepared with 0.3 g of urea reached 141% that of the sample prepared under the same conditions but without urea. The strategy for controlling the oriented growth, PL and EL enhancement of Y₂O₃:Eu³⁺ can be extended to the synthesis of other inorganic nano/ micromaterials.