Structure and luminescence properties of Eu3+-activated GaGd2SbO7 for light-emitting diodes

Eu 3+ -activated GaGd 2 SbO 7 phosphors were synthesized via the solid-state reaction method. XRD confirmed the formation of a single-phase cubic pyrochlore structure, with Eu 3+ occupying high-symmetry Gd 3+ sites. Under 266 nm excitation, both host-related broadband emission and sharp Eu 3+ 4 f −4 f transitions were observed. Increasing Eu 3+ concentration enhanced energy transfer efficiency with optimal luminescence at 30 mol% Eu 3+ . Under 394/466 nm excitation, comparable intensities of the 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 transitions confirm centrosymmetric site occupancy. The phosphors demonstrated an internal quantum efficiency of 88.19%, high color purity (>88%), strong thermal stability (71.6% intensity retention at 450 K), and a relatively high activation energy of 0.27 eV. Compared with previously reported Eu 3+ -based red phosphors, the Eu 3+ -activated GaGd 2 SbO 7 phosphors provide efficient excitation under both near-UV and blue light, highlighting their promise as a competitive candidate for high-power warm-white LEDs and other solid-state lighting applications.