A reddish orange-emitting stoichiometric phosphor K 3Eu(PO 4) 2 for white light-emitting diodes

Abstract

A series of Eu 3+ activated K 3Y 1− x Eu x (PO 4) 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 K 3Y(PO 4) 2 or K 3Eu(PO 4) 2. The excitation spectra indicate that these phosphors can be effectively excited by near UV (370–410 nm) light. The orange emission from transition 5D 0– 7F 1 is dominant, and the peak value ratio of 5D 0– 7F 1/ 5D 0– 7F 2 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 5D 0– 7F J transitions of Eu 3+ ions. The relationship between the structure and the photoluminescent properties of the phosphors was studied. The absence of concentration quenching of Eu 3+ was observed in K 3Y 1− x Eu x (PO 4) 2. K 3Eu(PO 4) 2 has potential application as a phosphor for white light-emitting diodes.