Structural and luminescence properties of red-emitting Cs1-xMgPO4:xEu2+ phosphors for near-UV-pumped light emitting diodes

A series of luminescent phosphate phosphors Cs1-xMgPO4:xEu(2+) were synthesized via a high temperature solid-state reaction. The phase structure and photoluminescence (PL) properties, as well as the PL thermal stability of Cs0.96MgPO4:0.04Eu(2+) were investigated to characterize the resulting sample. The crystal structure and chemical composition of the Cs0.96MgPO4:0.04Eu(2+) phosphor were analyzed based on the Rietveld refinements and the crystal chemistry rules, respectively. The optimum concentration of Eu2+ in the CsMgPO4 phosphor was about 4 mol% and the concentration quenching effect can be attributed to the dipole-dipole interaction. This phosphor shows a broad red emission band ranging from 500 to 800 nm under the 410 nm light excitation. The above results indicate that Cs1-xMgPO4:xEu(2+) phosphors have potential applications for near UV-excited w-LEDs.