Sol–gel preparation and characterization of uniform core-shell structured LaInO3:Sm3+/Tb3+@SiO2 phosphors

The core-shell structured LaInO3:Ln3+@SiO2 (Ln3+ = Sm3+, Tb3+) phosphors were realized by coating LaInO3:Ln3+ phosphors on the surface of silica microspheres via a modified Pechini sol–gel process. The phase, structure, morphology, and fluorescent properties of the materials were well characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform IR spectroscopy (FT-IR), photoluminescence (PL) spectra, cathodoluminescence (CL) spectra, and the kinetic decays, respectively. The results reveal that the obtained core-shell structured phosphors consist of amorphous silica core and crystalline LaInO3:Ln3+ shell, which keep the uniform spherical morphology of pure silica spheres with narrow size distribution. Upon excitation by ultraviolet (UV) irradiation or electron beam, the phosphors show the characteristic emission lines of Sm3+ (4G5/2–6H5/2,7/2,9/2, orange) in LaInO3:Sm3+@SiO2 and characteristic emissions of Tb3+ (5D4–7F6,5,4,3, green) in LaInO3:Tb3+@SiO2, respectively. This kind of phosphors may have potential applications in field emission displays (FEDs) based on their uniform shape, low-cost synthetic route, and diverse luminescent properties.

The core-shell structured LaInO3:Ln3+@SiO2 phosphors were realized by coating LaInO3:Ln3+ phosphors on the surface of silica microspheres via a modified Pechini sol–gel process.Figure optionsDownload as PowerPoint slideResearch highlights▶ A facile and low-cost sol-gel process was used to fabricate fluorescent microspheres. ▶ Uniform core-shell structured phosphors with bright PL emissions were obtained. ▶ The possible formation scheme for the core-shell structured spheres is presented.