Abstract: A series of Gd₂MgTiO₆ (GMT) white phosphors doped with different Dy³⁺ concentrations were prepared by the sol-gel method.The GMT:xDy³⁺(x=0.01, 0.03, 0.05, 0.07, 0.09, 0.11) samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and fluorescence spectroscopy. The research results show that the structure of the prepared series of fluorescent powders is monoclinic, and Dy³⁺ was successfully doped into GMT matrix without affecting the original crystal structure. The grain size of the sample is in the micrometer scale. Under near-ultraviolet excitation at 351 nm, the sample exhibits extremely strong blue and yellow light at 483 and 578 nm, respectively. The blue light is attributed to the ⁴F_9/2→⁶H_15/2 energy level transition of Dy³⁺, while the yellow light belongs to the ⁴F_9/2→⁶H_13/2 energy level transition of Dy the continuous increase of Dy³⁺ concentration, there is a significant concentration quenching phenomenon, which is attributed to the interaction between electric dipoles. When x=0.05, the CIE coordinates (0.324 71, 0.359 74) are relatively close to the CIE coordinates of standard white light (0.33, 0.33), indicating that GMT:Dy³⁺ is a single matrix white phosphor with potential application value.

Key words: GMT matrix, sol-gel method, Dy³⁺ monodoping, w-LED