Preparation And Luminescence Properties Of Eu³⁺ Doped Lu₂O₃/Lu₂O₂S Micro/Nanomatrials With Different Morphologies

Generally, the properties of inorganic micro/nanomaterials strongly depend onthe chemical composition, crystal structure, size, shape, and dimensionality. Therefore,preparation of well dispersed micro/nanostructures with tunable size and well-definedmorphologies have attracted extensive interests of scientists. Rare earth oxides/oxysulfides have been widely used in high-performance luminescent devices, magnets,catalysts, and other functional materials, due to their novel electronic characteristicsarising from the4f. Up to now, many kinds of rare earth oxides/oxysulfidesluminescent materials have been successfully synthesized by various of methods,including wire-like, rod-like, belt-like, tube-like, cube-like, sphere-like materials andso on. These micro/nano luminescent materials with special structures andmorphologies will have different properties. This paper mainly reports the preparationand luminescent properties of lutetium oxides and lutetium oxysulfides with specialmorphologies by solvothermal method. The main results of the research work are asfollows:1. Highly monodisperse and homogeneous SiO2@Lu2O3:Eu3+were synthesizedsuccessfully by the template method. The results show that the SiO2@Lu2O3:Eu3+core-shell structured microspheres are of pure cubic phase of Lu2O3, the corediameters of~360nm, and the shell thicknesses of~20nm, respectively. In addition,Upon excitation at393nm, photoluminescent emission spectra reveal characterisationof europium ions.2. Novel3D Lu2O2S:Eu3+sub-microstructures were successfully synthesizedwith polyvinylpyrrolidone (PVP) as surfactant, NaOH as pH adjusting agent, followedby a subsequent calcination process. The3D Lu2O2S:Eu3+sub-microstructures are justlike two twinned tetrahedra, slotted into each other. XRD、SEM and TEM resultsshow that Lu2O2S:Eu3+sub-microstructures are of pure hexagonal phase of Lu2O2Swith good dispersion and homogeneity, and the diameters is about700nm. Under UVlight excitation, the calcined3D Lu2O2S:Eu3+architectures exhibit strong red emission corresponding to the5D0�'7F2transition of the Eu3+ions. Such3Darchitectures with unique morphologies and excellent luminescence properties mayhave potential applications in the fields of display systems, optoelectronic devices andbiosensors.3. Highly crystalline and uniform Lu2O2S:Eu3+nanorods have been successfullysynthesized through a facile solvothermal method followed by a subsequentcalcination process. The Lu2O2S:Eu3+nanorods are pure hexagonal phase of Lu2O2Swith a mean diameter of22nm and length of500nm. The optimal annealingtemperature of Lu2O2S:Eu3+nanorods is600oC and5%is the quenchingconcentration of Eu3+in the systerm. The emission spectrum and decay curve of theEu3+(λex=270nm and λem=626nm) in the Lu2O2S nanorods reveal that Eu3+ionstake a low symmetry site without an inversion center in the Lu2O2S host lattice. Theionic radius of Eu3+is larger than that of Lu3+, so it is difficult for the Eu3+ions toenter the lattice of Lu2O2S and occupy the sites of Lu3+. Therefore, there are moreEu3+on the surface rather than in the “bulk”.