A reddish orange-emitting stoichiometric phosphor K3Eu(PO4)2 for white light-emitting diodes

A series of Eu3+ activated K3Y1−xEux(PO4)2 phosphors were synthesized by the solid-state reaction method. The structures and photoluminescent properties of these phosphors were investigated at room temperature. The results of XRD patterns indicate that these phosphors are isotypic to the monoclinic K3Y(PO4)2 or K3Eu(PO4)2. The excitation spectra indicate that these phosphors can be effectively excited by near UV (370–410 nm) light. The orange emission from transition 5D0–7F1 is dominant, and the peak value ratio of 5D0–7F1/5D0–7F2 is 1.44. The emission spectra exhibit strong reddish orange performance (CIE chromaticity coordinates: x=0.63, y=0.36), which is due to the 5D0–7FJ transitions of Eu3+ ions. The relationship between the structure and the photoluminescent properties of the phosphors was studied. The absence of concentration quenching of Eu3+ was observed in K3Y1−xEux(PO4)2. K3Eu(PO4)2 has potential application as a phosphor for white light-emitting diodes.

► The photoluminescence properties of K3Eu(PO4)2 were investigated in detail. ► We demonstrated that Eu3+ activated phosphor based on NUV LED should be heavy doped. ► The energy levels 5L6,7 and 5GJ of Eu3+ form a quasi-broad band in our phosphor.