Morphology-tailored synthesis and luminescent properties of Y₂O₃:Eu³⁺ phosphors

The size and shape of functional micro/nanomaterials have crucial influence on their physical and chemical properties. The monoclinic Y₄O(OH)₉NO₃ with nanosheets, submicrospheres, and microrods have been successfully prepared by a non-aqueous solvothermal method. The precursors Y₄O(OH)₉NO₃ decompose into cubic Y₂O₃:Eu³⁺ phosphors after sintering at 800 °C for 2 h. The morphologies and sizes of Y₂O₃:Eu³⁺ particles can be easily controlled by changing the growth rates of various crystallographic facets during solvothermal process. With the increment of the rare-earth nitrates concentration, the morphologies transform from 2D nanosheets to sub-microspheres, and eventually to microrods. The bright red emission, owing to Eu³⁺ f-orbital transitions, can be easily observed under ultraviolet excitation. Furthermore, the dependence of Y₂O₃:Eu³⁺ luminescence performances on different morphologies are discussed in the present work.