Effect of La³⁺ and Eu³⁺ Doping on Luminescence Performance of KAlSi₂O₆ Based Red Phosphor

Red phosphors K_1−xAlSi₂O₆∶xEu³⁺ and K_0.93−xAlSi₂O₆∶（0.07Eu³⁺+xLa³⁺） (x=0.01, 0.03, 0.05, 0.07, 0.09, 0.11,mole fraction） were prepared by high temperature solid-state method. The effects of La³⁺/Eu³⁺ doping on luminescence intensity, fluorescence lifetime and color coordinate were studied. The results show that after Eu³⁺ single doping or Eu³⁺+La³⁺ co-doping,the red phosphors were all composed of a leucite phase, and no new phase was found. With the increase of Eu³⁺ doping amount, the leucite phase changed from tetragonal structures to cubic structures. With the increase of Eu³⁺ doping amount, the luminous intensity of KAlSi₂O₆ red phosphor increased first and then decreased, and the intensity was the highest when the mole fraction of Eu³⁺ was 0.07. With the increase of La³⁺ doping amount, the luminous intensity of K_0.93AlSi₂O₆∶0.07Eu³⁺ red phosphor increased first and then decreased. When the mole fraction of La³⁺ was 0.09, the intensity was the highest, which was more than twice as much as that without La³⁺ doping. Compared with that of the single doping 0.07 mole fraction of Eu³⁺, the fluorescence lifetime of KAlSi₂O₆ based red phosphor co-doped with 0.07 Eu³⁺ and 0.09 La³⁺ was longer. The color coordinate under co-doping Eu³⁺+La³⁺ moved from orange of single doping Eu³⁺ to red, and the red component was more obvious, showing excellent red emission performance.