Non-concentration quenching phosphor Na2YbMg2(VO4)3: Eu3+ for WLEDs and optical thermometry applications

Abstract

Red-emitting phosphors with high efficiency and good thermal stability is of great importance for white light-emitting diodes (WLEDs) application. Here, Eu3+ doped Na2YbMg2(VO4)3 red-emitting phosphors were successfully prepared by the sol-gel method. The crystal structures, luminescence properties, and thermal stability of the samples were investigated and discussed in detail. Surprisingly, no concentration quenching effect was observed even though the doping concentration of luminescent centers reach 100 %. The intense red emission under 355 nm excitation, high color purity (95.34 %), high quantum yield (75.2 %), and a high value of activation energy (0.293 eV) indicate that the phosphors have promising applications for WLEDs. Finally, the samples were prepared as red-light components for WLEDs. The correlated color temperature, and color rendering index of the WLEDs devices driven by 400 mA current were 4902 K, and 78.1, respectively. The temperature sensing properties based on the fluorescence intensity ratio (FIR) technique was discussed. The maximal absolute sensitivity of the sample is up to 5.08 % K−1 at 480 K. Hence, the as-prepared sample has potential applications in the lighting field and optical thermometry.