(Ln3+ = Eu3+/Dy3+/Dy3+, Eu3+) doped NaGd(MoO4)2 phosphors with uniform morphologies: Hydrothermal synthesis, luminescent properties, energy transfer and color tunable emission

Abstract

NaGd(MoO4)2: Ln3+ (Ln3+ = Eu3+/Dy3+/Dy3+, Eu3+) phosphors were prepared by the facile hydrothermal process using sodium citrate as surfactant. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), photoluminescence (PL). The results indicate that all the samples with shuttle morphology were tetragonal. The energy transfer from Dy3+ to Eu3+ was determined by photoluminescence (PL) spectra and fluorescence lifetimes. The energy transfer mechanism from Dy3+ to Eu3+ was confirmed to be a dipole-dipole mechanism. Moreover, the color-tunable emissions with excitation at 353nm were realized in the NaGd(MoO4)2: Dy3+, Eu3+ microcrystals, and the colors changed from yellow to white to pink. So these phosphors can be favorable candidates in solid state lighting.