Synthesis and luminescence properties of Eu²⁺/Ce³⁺ co-doped SrB₂Si₂O₈ phosphor

SrB₂Si₂O₈: Eu²⁺/Ce³⁺ co-doped phosphors were synthesized via conventional high temperature solid state reaction method. The best rare earth doping SrB₂Si₂O₈ phosphors were obtained at 950 °C for 6 h. For SrB₂Si₂O₈: Eu²⁺, a large broad band locating at 440 nm corresponding to the 4f⁶5d-4f⁷ (⁸S_7/2) transition. The optimal concentration of Eu²⁺ is 8 at.%, its concentration quenching is due to dipole–dipole interaction. Under UV excitation of 320 nm, SrB₂Si₂O₈: Ce³⁺ phosphor demonstrates a strong emission peak located at 373 nm. By Gaussian fitting, the emission of the sample peaking at 367 nm (27223 cm⁻¹) and 396 nm (25270 cm⁻¹) corresponding to the transition 5d–4f (²F_5/2) and 5d–4f (²F_7/2), respectively, the best doping concentration of Ce³⁺ is 0.6 at.%. Simultaneously, a series of Sr_1−xB₂Si₂O₈: xEu²⁺, Ce³⁺ phosphors were studied, results indicating that the emission intensity of Ce³⁺ ions decreases with the increasing of Eu²⁺ concentration, when the doping concentration of Eu²⁺ reaches 1.0 at.%, the emitting intensity is 2.1 times higher than that of the single doped Eu²⁺. The energy transfer efficiency among Ce³⁺ and Eu²⁺ ions is calculated to be as high as 93.4%, which is caused by the dipole–dipole resonant type from Ce³⁺ to Eu²⁺.