Enhanced red emission and high thermal stability from Bi3+/Eu3+ co-doped Ba3Y(BO3)3 phosphors for WLEDs application

Highlights: • A red-emitting phosphor Ba₃Y(BO₃)₃:Bi³⁺, Eu³⁺ was synthesized. • The red emission intensity of Eu³⁺ is significantly enhanced by doping a small amount of Bi³⁺. • The emission intensity at 423 K maintained 80.7% of the initial intensity at room temperature (298 K). A series of Bi³⁺/Eu³⁺ co-doped Ba₃Y(BO₃)₃ red-emitting phosphors were successfully prepared by the combustion method. The crystal structure and photoluminescence properties of the as-prepared phosphors were investigated by X-ray powder diffraction, photoluminescence excitation and emission spectra. In this paper, the Bi³⁺ ion was employed as a sensitizer to improve the red emission intensity of Eu³⁺. The optimal doping concentration of Bi³⁺ was 1 mol%. The observed excitation broad bands centered at 300 nm confirmed Bi³⁺ ion doped into the Ba₃Y(BO₃)₃ host. The red emission intensity of Eu³⁺ was significantly enhanced by doping a small amount of Bi³⁺. Furthermore, Bi³⁺/Eu³⁺ co-doped phosphor possessed admirable thermal stability (the emission intensity of studied phosphor at 423 K maintained 80.7% of the initial intensity at room temperature). The results manifest that Bi³⁺ ion is an efficient sensitizer for Eu³⁺ ion and Ba₃Y(BO₃)₃: 24 mol% Eu³⁺, 1 mol% Bi³⁺ phosphors possess a great potential for applications in white LEDs.