Morphology and photoluminescent properties of KLa(MoO_4)_2 (doped with Eu~(3+)) synthesized by a molten salt method

摘要

Octahedron-like KLa(MoO_4)_2 microcrystals with monoclinic scheelite-type structure were successfully synthesized by a low cost molten salt method using KCl as flux. The as-prepared products were characterized by powder X-ray diffractometer (XRD), scanning electron microscope (SEM) and photoluminescence spectrometer (PL). The results indicate that calcining temperature and reaction time have great impacts on the morphologies and sizes of the product. The emission spectra recorded for an excitation wavelength at 289 nm exhibit a strong emission peak at 616 nm, corresponding to the ~5D_0→~7F_2 transition of Eu~(3+). The quenching concentration was found at 15 mol% doping of Eu~(3+). The commission international Del'Eclairage (CIE) chromaticity coordinates of the phosphors were about (0.6632, 0.3365) and it is very close to the standard red chromaticity of NTSC. Therefore, the phosphors could be promising for white light-emitting diodes.