Synthesis And Photoluminescent Properties Of Eu³⁺-doped Alkaline Earth Metal Molybdate/ Tungstate Molybdate Red Phosphors For LED Applications

A1-xBxMoO4:0.01Eu(A/B=Ca, Sr, Ba; x=0.2, 0.4, 0.5, 0.6, 0.8),A1-xBxMoO4:yEu(A=Ca/Ba, B=Sr; x=0.4, 0.6; y=0.01, 0.08, 0.20) and A(WO4)1-x(MoO4)x:0.01Eu(A=Ca, Sr, Ba; x=0.2, 0.4, 0.5, 0.6, 0.8) phosphors were prepared successfully by solid state method. At the same time, for the optical properties of Alkaline earth metal molybdate /tungstate phosphors, the factors of the components of cations and anions, and the amount of RE Eu3+ doped were studied systematically. Some main research results as follows:A1-xBxMoO4:0.01 Eu and contrastive samples phosphors were prepared successfully by solid state method. The structure and photoluminescent properties are systematically studied. The XRD patterns of Ca1-xSrxMoO4:0.01Eu3+ and Ba1-xSrxMoO4:0.01Eu3+ phosphors were shown that them form stable solid solution and the value of cell parameters regularly change with the value of x increasing. However, Ca1-xBaxMo O4:0.01Eu3+ phosphors did not form solid solution. If the cations of samples were Ba and Sr, the intensity of 4f–4f transitions of Eu3+ ion would be increased to the strongest one; If the cations were Ca and Sr, it would be increased to the stronger one; If the cations were Ca and Ba, the effect would be the worst.A1-xBxMoO4:yEu and contrastive samples phosphors were prepared successfully by solid state method. The structure and photoluminescent properties are systematically studied. The XRD patterns were shown that the Eu3+ ions have been entered into the crystal lattice of samples. However, when the value of y is greater than0.08, Eu2O3 phase was observed in some samples. The FESEM images of A1-xBxMoO4:yEu phosphors were shown such an interesting phenomenon. When y=0.20, there exist a large number of smaller particles on the large particle surface. According to the results of phase analysis of the XRD patterns, those smaller particles were maybe Eu2O3. It is important and interesting that the quenching concentration of Eu3+ in Ba0.4Sr0.6MoO4:0.20Eu3+ phosphor is as high as 20%.A(WO4)1-x(MoO4)x:0.01 Eu and contrastive samples phosphors were prepared successfully by solid state method. The structure and photoluminescent properties are systematically studied. The XRD patterns were shown that all samples have been formed stable solid solution without the mixed phase. The results showed that Ca(WO4)1-x(MoO4)x:0.01 Eu and Sr(WO4)1-x(MoO4)x:0.01 Eu phosphors didn’t enhanced the Red-light emission too much. However, when it was excited at 395 nm or 465 nm, Ba(WO4)0.2(MoO4)0.8:0.01Eu3+ phosphor showed a very strong red light emission. That is to say, it may be having a widely application in the field of W-LED.