Preparation of a novel red KBaGd(MoO4)3:Eu3+ phosphor by sol-gel method and its luminescent properties.

Abstract For the first time, KBaGd(MoO 4) 3 :Eu3+ phosphors were synthesized by sol-gel method and its structure, morphology and luminescent properties were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), excitation and luminescent spectra. The results show that shape and the particle size distribution of samples synthesized by sol-gel method were more regular and narrower than those synthesized by solid state method. Under the excitation of near UV light (395 nm), an intensive red emission band around 617 nm corresponding to the transition of 5D 0 →7F 2 was observed. The effects of the dose of citric acid, pH value of precursor solution and concentration of Eu3+ ions on the morphology and luminescent properties of the samples were also analyzed. The phosphors show the highest emission intensity as the molar ratio of citric acid to metal ions (C:M) was 2:1, and the optimum concentration of Eu3+ was x = 0.8. The thermal stability of the KBaGd 0.2 (MoO 4) 3 :0.8Eu3+ phosphor was investigated in the framework of crossover mechanism, and the activation energy was determined to be 0.264eV. Lastly, a red LED was fabricated using the as-synthesized phosphor and its luminescent performances were investigated. Highlights • For the first time, KBaGd(MoO 4) 3 :Eu3+ phosphors were synthesized by sol-gel method. • The FT-IR, excitation and emission spectra, luminescent decay curves of the samples were recorded. • The effects of citric acid concentration, pH value on the morphology and luminescent properties of the samples were analyzed. • The thermal stability of the KBaGd 0.2 (MoO 4) 3 :0.8Eu3+ phosphor was investigated in the framework of crossover mechanism. • A red LED was fabricated using the as-synthesized phosphor and its luminescent performances were investigated. [ABSTRACT FROM AUTHOR]