Uniform lanthanide-doped Y2O3 hollow microspheres: Controlled synthesis and luminescence properties

Lanthanide-doped uniform pure cubic phase Y2O3 hollow microspheres have been successfully synthesized via a facile, high yield urea-based coprecipitation route with assistant of carbon spheres templates. The diameter and shell thickness of the microspheres can be manipulated by adjusting carbon sphere templates. Under a 980 nm excitation, Yb3+/Er3+, Er3+, Yb3+/Tm3+-doped Y2O3 hollow microspheres emit bright upconversion red, green, blue light with high purity, respectively, while Eu3+, Eu3+/Tb3+-doped Y2O3 hollow microspheres exhibit intense downconversion red light under the excitation of 254 nm ultraviolet light. Especially, the 610 nm emission intensity of Eu3+ in the Eu3+/Tb3+-codoped Y2O3 hollow microspheres is almost 5 times of that in the Y2O3:Eu3+ hollow microspheres indicating the occurring of the energy transfer from Tb3+ to Eu3+ ions.