Luminescent properties of Eu 3+ -activated Gd 2 ZnTiO 6 double perovskite red-emitting phosphors for white light-emitting diodes and field emission displays.

We synthesized a series of double perovskite Eu 3+ -activated Gd 2 ZnTiO 6 red-emitting phosphors by a solid-state reaction route and analyzed their morphology, crystallinity, luminescent properties, and thermal stability. Under 270 nm of excitation, the prominent emission peak of the phosphors was found to be located in the red region with the central wavelength of 613 nm corresponding to the intra-4f transition of Eu 3+ ions from the 5 D 0 to 7 F 2 level. The optimum concentration of the activator was determined to be 7 mol%. The studied phosphors also exhibited good thermal stability with the activation energy of 0.233 eV. The white color emitted from the ultraviolet (UV) light-emitting diode device which was coated by commercial blue-/green-emitting phosphors and Gd 1.86 ZnTiO 6 :0.14Eu 3+ phosphors exhibited a high color rendering index of 82.9. Furthermore, the cathodoluminescence performance of the resultant phosphors was also investigated in detail. These characteristics of Gd 2-2 x ZnTiO 6 :2 x Eu 3+ phosphors make them potential candidates for UV-based white light-emitting diodes and field emission displays.