Photoluminescence enhancement in a Na5Y(MoO4)4:Dy3+ white-emitting phosphor by partial replacement of MoO42− with WO42− or VO43−.

A series of Na 5 Y(MoO 4) 4- y A y :Dy3+ (A = WO 4 2−, VO 4 3−; y = 0–0.05) phosphors were synthesized by the combustion method. Some of the MoO 4 2− sites were occupied by WO 4 2− and VO 4 3− anions, which enhanced the luminescence property of Dy3+-doped Na 5 Y(MoO 4) 4. XRD results show that the crystal structures of the samples were consistent with the standard Na 5 Y(MoO 4) 4 phase. Under excitation at 352 nm, the Na 5 Y(MoO 4) 4- y A y :Dy3+ phosphors exhibited a characteristic blue emission at 485 nm and a yellow emission at 577 nm, which originated from the 4F 9/2 → 6H 15/2 and 4F 9/2 → 6H 13/2 transitions of Dy3+ ions, respectively. White light can be achieved by combining these blue and yellow emissions. After replacing MoO 4 2− with WO 4 2− and VO 4 3− anions in Na 5 Y(MoO 4) 4 :Dy3+, the luminescence intensity of Dy3+ was significantly improved due to the crystal field effect. The results indicate that Na 5 Y(MoO 4) 3. 97 (WO 4) 0.03 :Dy3+ and Na 5 Y(MoO 4) 3. 97 (VO 4) 0.03 :Dy3+ phosphors have good prospects for application in n-UV-excited w-LEDs. [ABSTRACT FROM AUTHOR]