Preparation and luminescence properties of Ce³⁺-doped Gd₅Si₃O₁₂N phosphor emerging red shift

Blue-emitting phosphors (Gd_1-xCe_x)₅Si₃O₁₂N (0 ≤ x ≤ 0.07) were prepared through a solid-state reaction under a reducing atmosphere. The excitation spectra exhibited several broad bands in the wavelength range from 240 to 400 nm, and the emission spectra consisted of a broad band covering from 360 to 550 nm. Two different emission centers corresponding to two different crystallographic sites in the host lattice were confirmed. The influence that the Ce³⁺ concentration had on the photoluminescence of the prepared samples was examined, and the results indicate that an increase in the Ce³⁺ concentration introduces a red-shift of the emission peak due to an increase in the Stokes shift. Concentration quenching occurs when the Ce³⁺ content exceeds 3 mol%. In addition, the configurational coordinate model was used to finely explain the thermal quenching behavior of the phosphors.