High quantum efficiency red-emission tungstate based phosphor Sr(La1−xEux)2Mg2W2O12 for WLEDs application

A series of red-emitting Eu3+-doped phosphors SrLa2Mg2W2O12 were successfully prepared by the solid state reaction and their luminescence properties were investigated in detail. Under 464 nm light excitation, the emission intensity at 613 nm increased with the Eu3+ ion concentration rising, and the quenching effect did not appear until the Eu3+ ion concentration reached 25%, and the critical distance was calculated to be 7.74 Å. The emission intensity of Sr(La0.75Eu0.25)2Mg2W2O12 is approximately three times higher than that of the commercial red phosphor Y2O3:Eu3+ under the blue light, meanwhile, the quantum efficiency of Sr(La0.75Eu0.25)2Mg2W2O12 is about two times higher than that of Y2O3:Eu3+. The Commission Internationale de l′Eclairage chromaticity coordinate of Sr(La0.75Eu0.25)2Mg2W2O12 is (x=0.660, y=0.340), which is closed to the standard of NTSC (x=0.670, y=0.330). The results indicate that Sr(La1−xEux)2Mg2W2O12 could be a potential red phosphor in fabrication of blue chips WLEDs.