Photoluminescence studies of high-efficient red-emitting K 2 Y(WO 4 )(PO 4 ):Eu 3+ phosphor for NUV LED

Abstract A series of high-efficient red-emitting phosphors K 2 Y(WO 4 )(PO 4 ):Eu 3+ have been successfully synthesized by conventional solid-state reaction, and its photoluminescence (PL) properties have been investigated. The phosphors can be excited efficiently by NUV light, then exhibit strong red emission with quantum efficiency of 70.5%. The concentration quenching takes place at relatively high concentration of Eu 3+ ( x = 0.70), which is further confirmed by the variation of decay curves of the entitled phosphors. Judd–Ofelt analysis ascertains the presence of Eu 3+ in a highly asymmetric environment. The phosphor exhibits good thermal stability (92.5% at 100 °C and 84.1% at 180 °C). The red LED prototype fabricated by opyimized-composition K 2 Y(WO 4 )(PO 4 ):0.70Eu 3+ phosphor and 395 nm-emitting InGaN chips exhibit bright red emission. The results indicate that the K 2 Y(WO 4 )(PO 4 ):Eu 3+ phosphors are promising red phosphors for NUV LED.