Synthesis, luminescent properties, and thermal stabilities of Gd2(1-x)Eu2x(MoyW1-yO4)3 (0≤x≤0.2, 0≤y≤1) solid solution phosphors

Abstract

Through a solid-state reaction method, Gd2(1-x)Eu2x(MoyW1-yO4)3 (0 ≤ x ≤ 0.2, 0 ≤ y ≤ 1) solid solution phosphors were synthesized. The crystalline structures, the morphologies, and the compositions of the solid solution phosphors were characterized by X-ray diffraction (XRD) patterns, field emission scanning electron microscope (FE-SEM) images, energy-dispersive spectra (EDS), respectively. The diffuse reflection spectra (DRS), room temperature photoluminescence (PL) excitation and emission spectra, luminescence decay curves, and high temperature PL spectra were recorded to characterize the luminescent properties, the luminescent dynamics, and the thermal behaviors of the phosphors. The synthetic temperatures were explored to determine the optimal synthetic temperature. The Eu3+ concentration quenching effects were observed in the orthorhombic phase of Gd2(1-x)Eu2x(MoO4)3 phosphors and the monoclinic phase of Gd2(1-x)Eu2x(WO4)3 phosphors. By introducing Mo6+ to Gd2(1-x)Eu2x(MoyW1-yO4)3 phosphors, crystalline phase variations and red shift excitation bands were recorded. Enhancing Eu3+ excitation and emission intensities were recorded in the Gd2(1-x)Eu2x(MoyW1-yO4)3 solid solution phosphors with the concentration of W6+ increasing. The obtained Gd2(1-x)Eu2x(MoyW1-yO4)3 phosphors can be used in phosphor converted based ultraviolet (UV) LEDs.