Preparation and characterization of nanosized Gd_xBi_0.95-x VO₄：0.05Eu³⁺ solid solution as red phosphor

A complete solid solutions with monophasic zircon-type structure of vanadates of formula Gd_xBi_0.95-xVO₄:0.05Eu³⁺ (x=0-0.95) are synthesized by combined method of co-precipitation and hydrothermal synthesis. Their microstructures and morphologies are characterized by X-ray powder diffraction and transmission electronic microscope, and the results show that each of all the samples has a monophasic zircon-type structure. The absorption spectrum of the prepared phosphor shows a blue-shift of the fundamental absorption band edge with increasing the gadolinium content. Under UV-light and visible-light excitation, all the prepared phosphors show the typical luminescence properties of Eu³⁺ in the zircon-type structure. The emission intensity of Gd_xBi_0.95-xVO₄:0.05Eu³⁺ (x=0.55) is strongest in all samples under UV-light and visible-light excitations. Finally, the mechanisms of luminescence of Eu³⁺ in the Gd_xBi_0.95-xVO₄:0.05Eu³⁺ (x=0-0.95) solid solutions are analyzed and discussed.