Synthesis and luminescence properties of a novel red-emitting phosphor Ba3La(PO4)3:Eu3+ for solid-state lighting

A novel series of Ba3La(PO4)3:xEu3+ (0.01 ⩽ x ⩽ 1.00) phosphors was prepared by the convenient solid-state reaction. The structural and photoluminescent properties of the phosphors were carefully studied. The X-ray powder diffraction analysis confirmed the formation of the complete solid solutions between Ba3La(PO4)3 and Ba3Eu(PO4)3. The photoluminescence spectra showed that the samples had intense and prevailing red emissions at 610 nm belonging to the 5D0 → 7F2 electric dipole transition. The optimum dopant concentration of Eu3+ ions in Ba3La(PO4)3:xEu3+ was around 90 mol%, and the critical transfer distance of Eu3+ was calculated to be 8.4 Å. The quenching temperature for Ba3La0.10(PO4)3:0.90Eu3+ was estimated to be above 500 K. Under 394 nm excitation, the quantum efficiency of Ba3La0.10(PO4)3:0.90Eu3+ was determined to be ∼71%. Therefore, Eu3+-doped Ba3La(PO4)3 phosphors are potential red phosphors for NUV chip-based WLEDs and display devices.