Effects of deionized water modification of raw materials on properties of Ca₆BaP₄O₁₇:Eu²⁺ phosphate phosphors

Ca₆BaP₄O₁₇:Eu²⁺ phosphate phosphors were synthesized from raw materials with and without deionized (DI) water modification using a conventional solid-state reaction method. A comparison of raw materials with and without DI water modification was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis/differential scanning calorimetry. The phosphor morphologies and crystal structure were studied using SEM and XRD, respectively. The excitation and emission characteristics were investigated using photoluminescence spectroscopy. The Ca₆BaP₄O₁₇:Eu²⁺ phosphor can be efficiently excited by near-UV (ultraviolet) and blue light. Under 397-nm excitation, the phosphor exhibited a yellow broad-band emission centered at 550 nm, which derives from the 4f⁷–4f⁶5d¹ transition of Eu²⁺ ions. By introducing DI water into the ground raw materials of the phosphate phosphor, the synthesis temperature can be reduced, enhancing the emission intensity and crystal purity of the phosphor. The results suggest that sintering a mixture of DI-water-modified raw materials is a good approach for synthesizing phosphate phosphors as it improves photoluminescence and crystal structure. The prepared phosphors have potential to be coupled with near-UV and blue LED chips.