Synthesis and Comparison of Eu³⁺ Doped M-Gd₂(MoO₄)₃ and O-Gd₂(MoO₄)₃ Phosphors

The Eu3+ doped monoclinic phase of Gd2(MoO4)3 (M-Gd2(MoO4)3) and the Eu3+ doped orthorhombic phase of Gd2(MoO4)3 (O-Gd2(MoO4)3) red phosphors were synthesized by adjusting the synthesis temperatures. The XRD (X-ray diffraction) patterns, the EDS (energy-dispersive spectra), and the FE-SEM (field emission scanning electron microscope) images were used to comparatively study crystalline structures, compositions, and morphologies of the two materials. The DRS (diffuse reflection spectra), the room and high temperature PL (photoluminescence) spectra, and the fluorescence decay curves were recorded to compare the PL properties of the two phosphors. The characterization results suggest that the M-Gd2(MoO4)3 phosphor has lower synthesis temperature, while the O-Gd2(MoO4)3 phosphor has bigger particles, larger energy band gap value, stronger PL intensities, longer lifetimes, and better thermal stabilities. For Eu3+, the research results prove that the O-Gd2(MoO4)3 is a better host material choice than that of the M-Gd2(MoO4)3.