Photoluminescence properties of red europium doped calcium tungstate phosphors for blue-pumped light-emitting diodes

摘要

A series of stable CaWO4:Eu3+ phosphors have been prepared by the hydrothermal method. Eu2O3 (99.99%), CaCl2 (A.R.), Na2WO4 center dot 2H(2)O (A.R.) are raw materials. The luminescent properties of the phosphors have been investigated by the different contents of the dopants in CaWO4 and the optimum concentration of as-synthesized phophors is 1.5 wt%. The structure, morphology and luminescent properties of the phosphors are characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectroscopy technology. The results showed that introduction of Eu did not change the crystal structure and morphology of CaWO4:Eu3+ phosphors. The strongest emission at 614nm is corresponding to D-5(0) -{L-End} > F-7(2) transition of Eu3+ under 464 nm blue light excitation. The result reveals that CaWO4:Eu3+ is a promising red-emitting phosphor for blue LED applications. (C) 2015 Elsevier GmbH. All rights reserved.