Photoluminescence and cathode-luminescence of Eu³⁺-doped NaLnTiO₄ (Ln = Gd and Y) phosphors

Eu³⁺-activated layered perovskite ionic conductors NaYTiO ₄ and NaGdTiO₄ red-emitting phosphors were successfully synthesized by a modified sol-gel method for applications in field emission displays (FEDs) and ultraviolet-based light-emitting diodes (LEDs). The optimal compositions and parameters of synthesis were determined. The structure and luminescent properties were investigated by X-ray diffraction (XRD), photoluminescence excitation (PLE) and emission (PL) spectra. The cathode-luminescence (CL) spectra of phosphors as a function of accelerating voltage and filament current were also measured. The thermal stabilities and decay curves of phosphors were also investigated. The Eu³⁺-doped NaYTiO₄ phosphor offers higher brightness and thermal stability than Eu³⁺-doped NaGdTiO₄ in identical conditions. The former is the more suitable red-emitting phosphor candidate for LEDs and FEDs.