Double perovskite (Gd_0.85-xY_x)₂MgTiO₆:0.3Eu³⁺ red phosphors for white LEDs with excellent high temperature performance

The double perovskites of Gd₂MgTiO₆:0.3Eu³⁺ red phosphors doped by Y³⁺ in A-site with high temperature stability were successfully prepared by high temperature solid state reaction. X-ray diffraction and high-resolution transmission electron microscopy were utilized to discuss the rock-salt ordering structure of Gd₂MgTiO₆ double perovskite. The optical properties were analyzed by reflectance, excitation and emission spectra obtained by UV–Vis spectrophotometer and fluorescence spectrometer. When the Y³⁺ substitution amount is x = 0.4, the red-light intensity at 615 nm reached its maximum under the excitation of the near ultraviolet and blue light bands. As for thermal stability, the as-prepared phosphors could still maintain 81.98% of the luminous intensity at 473K, exhibiting excellent high temperature fluorescence properties. The A-site ion doped phosphors also display a longer fluorescence lifetime.