Controlled synthesis and luminescent properties of assembled spherical YPxV1−xO4:Ln3+ (Ln = Eu, Sm, Dy or Tm) phosphors with high quantum efficiency

Abstract

YP_xV_1−xO₄ (x = 0.3–0.9) assembled spheres with tetragonal phase were prepared hydrothermally under a simple and mild method with the assistance of EDTA. The structures and shapes of the prepared samples were significantly affected by the reaction conditions (hydrothermal treatment time, organic additive, pH value and the amount of EDTA in the synthesis solution). The characteristic emission of the spherical YP_xV_1−xO₄:Ln³⁺ (Ln = Eu, Sm, Dy or Tm) phosphors were investigated in detail. The results showed that the light color of the YP_0.3V_0.7O₄ microspheres can be easily adjusted by doping different lanthanide activators; Y_0.93Sm_0.07P_0.3V_0.7O₄ and Y_0.95Eu_0.05P_0.3V_0.7O₄ exhibited strong orange-red and red emission, respectively, and Y_0.93Sm_0.07P_0.3V_0.7O₄ has a higher quantum efficiency of 76.8%. For the Y_0.97Dy_0.03P_xV_1−xO₄ (x = 0.3–0.9) samples, both emission intensities of Dy³⁺ and VO₄³⁻ increase with increasing the P amount, and the quantum efficiency of Y_0.97Dy_0.03P_0.9V_0.1O₄ can reach 92%. It can also be found that the light color of the Y_0.97Dy_0.03P_xV_1−xO₄ samples can be tuned by changing the ratio of P/V, and Y_0.97Dy_0.03P_0.5V_0.5O₄ can emit white light under UV excitation.