Molten salt synthesized Tb³⁺, Pr³⁺ or Dy³⁺ single doped CaTa₄O₁₁ with persistent luminescence

A series of Tb³⁺, Pr³⁺ and Dy³⁺ monodoped CaTa₄O₁₁(CTO) persistent luminescence (PersL) phosphors have been successfully synthesized using the molten salt method with KCl flux. The PersL color is green and orange for Tb³⁺ and Pr³⁺ or Dy³⁺ doped samples, respectively. The trap depth of Tb³⁺, Pr³⁺ and Dy³⁺ monodoped CTO is 0.33, 0.31 and 0.30 eV, respectively. The PersL time of 3 mol% Tb³⁺, 1 mol% Pr³⁺ and 1 mol% Dy³⁺ monodoped samples is 52.20, 35.00 and 59.46 s, respectively. Tb³⁺, Pr³⁺ and Dy³⁺ monodoped CTO phosphors can be used in luminescence displays and anti-counterfeit labels under commercial 254 nm UV light.