Eu3+ and Tb3+ ions singly activated Gd2O2S hollow spheres have been successfully synthesized via solvothermal method by using Gd (NO3)3, Eu (NO3)3, Tb (NO3)3 and thiourea as raw materials. Detailed characterization of the as-prepared samples were obtained by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), transmission electronic microscope (TEM) and photoluminescence (PL) spectroscopy. The results demonstrate that at 220 oC for 24 h, the molar ratio of thiourea/Gd3+ has no significant impact on the phase composition of Gd2O2S products. With the reaction time increased from 6 h to 24 h, the morphology of Gd2O2S samples changed from ellipsoidal to near-spheroidal structure, but still remained hollow structure. PL results show that the strongest emission peaks for Gd2O2S:Eu3+ and Gd2O2S:Tb3+ samples were centered at 625 nm and 545 nm, corresponding to the 5D0→7F2 transition of Eu3+ ions and 5D4→7F5 transition of Tb3+ ions, respectively. The quenching concentrations for Eu3+ and Tb3+ ions were 12% and 6%, which can be attributed to the exchange interaction for Eu3+ and Tb3+ ions, respectively.
A series of Eu3+ ions activated La2O2SO4 nanophosphors had been prepared successfully by a facial co-precipitation route followed by a subsequent calcination treatment. The commercial Eu2O3, La2O3, HNO3, (NH4)2SO4 and NH3·H2O were used as the raw materials. The structural analyses and luminescence properties of as-prepared products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and photoluminescence (PL) spectra. Pure La2O2SO4 quasi-sphere nanoparticles with an average diameter of 40 nm were successfully prepared by calcining the precursor at 800 °C for 2 h in air. PL results reveal that the strongest red emission peak is centred at 617 nm upon 393 nm light excitation, corresponding to the 5D0→7F2 transition of Eu3+ ions. Its quenching concentration is 9 mol%, which can be attributed to the exchange interaction among Eu3+ ions and the corresponding decay process shows a double exponential decay behavior, with 0.310 μs for t1 and 1.419 μs for t2.
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