Influence of salt species on crystallization, morphology and luminescence properties of Ba2Y(BO3)2Cl:Eu3+ phosphor

Ba2Y(BO3)2Cl:Eu3+ microspheres, rods, columns and hexagonal flakes are synthesized via a facile molten salt synthesis (MSS) method by simply changing the salt species and adjusting the dosage of the molten salts. The X-ray diffraction (XRD) patterns suggest that the crystals have different preferential orientation growth under different molten salt conditions. Then transmission electron microscopy (TEM) results present that the micro-rods show a good crystallinity and the growth direction [4¯65]. When KCl is used as the molten salt, the sample with near spherical morphology shows the strongest emission at 593 nm which is due to 5D0-7F1 transition of Eu3+. While the samples that grow in NaCl or Na2SO4 environment show the strongest emission at 611 nm which is attributed to 5D0-7F2 transition of Eu3+. The lifetimes of the samples that used KCl, NaCl and Na2SO4 as molten salt are 1.99 ms, 1.93 ms and 2.33 ms, respectively. The reasons of how salt species to affect the crystallization, morphology and luminescence properties are discussed.