Template-free Fabrication and Luminescent Characterization of Highly Uniform and Monodisperse Y2O2S:Sm3+ Hollow Submicrospheres

Well dispersed and homogeneous Y2O2S:Sm3+ hollow submicrospheres were successfully achieved by a templatefree solvothermal method combining with a postcalcining process. The crystalstructure and particle morphology were investigated by the X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, scanning and transmission electron microscopy (SEM and TEM), respectively. A possible growth mechanism was proposed to reveal the formation process. Luminescence properties of the Y2O2S:Sm3+ long-lasting phosphor were analyzed by measuring the excitation spectra, emission spectra, afterglow decay curve and thermoluminescence curve. The excitation spectra indicated that the phosphor could be excited effectively by the ultraviolet-light emitting diode (UV-LED) or blue LED, and the emission spectra showed that the phosphor could emit red light from 600 to 650 nm.