Preparation and Characterization of Double Perovskite Sr₂GdSbO₆:Eu³⁺ Phosphor

The Sr₂GdSbO₆:Eu³⁺ red phosphor with double perovskite structure was successfully prepared by high temperature solid phase method and its XRD, photoluminescence spectrum and fluorescence decay lifetime were characterized. The XRD of the Sr₂Gd_0.8SbO₆:0.2Eu³⁺ phosphor is basically consistent with the peak position of the standard card, indicating that the doping of Eu³⁺did not change the crystal structure of the matrix. The crystal parameters after Rietveld refinement also verify the result. The photoemission spectrum shows that the sample has a wide excitation area centered at 340 nm in the ultraviolet region; under the excitation of a 340 nm light source, the strongest emission of the sample is an orange-red emission band with a center wavelength of 593 nm. Using Dexter theory to analyze the concentration quenching mechanism of the sample is the dipole-dipole interaction. The fluorescence decay life of Sr₂Gd_0.8SbO₆:0.2Eu³⁺ phosphors at room temperature is 4.202 ms, and the external quantum efficiency is 24.8%. When the temperature is raised to 150 ℃, the external quantum efficiency remains 68.8% of that at room temperature. The calculated color purity of Sr₂GdSbO₆:Eu³⁺ phosphor can reach 99.5%. Sr₂Gd_0.8SbO₆:0.2Eu³⁺ phosphor, blue phosphor, green phosphor and 365 nm UV chip package were made into LED devices which can emit bright white light. These results indicate that Sr₂GdSbO₆:Eu³⁺ phosphor is a potential red phosphor for white LED.