Europium-Activated KSrPO4–(Ba,Sr)2SiO4 Solid Solutions as Color-Tunable Phosphors for Near-UV Light-Emitting Diode Applications


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This article reports the structural and luminescence characteristics of Eu2+-activated solid solutions of (KSrPO4)1−x·((Ba,Sr)2SiO4)x for 0 ≤ x ≤ 1. These phosphors were prepared by a sol-gel/Pechini method. The lattice parameters of the solid solutions are linearly dependent on x. The reliability factor from Rietveld analysis is nearly constant and independent of x, indicating KSrPO4·(Ba,Sr)2SiO4 forms an ideal solid solution. The emission spectra consist of two distinct broad bands, which depend on x: blue ranging from 430 to 470 nm and green–yellow ranging from 515 to 570 nm. Both emission peaks red-shift as x increases due to the crystal field effect and an anomalous transition. The emission intensity of these solid solutions is also a function of x and is comparable to that of LiCaPO4:Eu2+ (QE = 81%) at x = 0.1, suggesting that these color-tunable solid solutions are promising for applications in solid-state white lighting.