Tailoring of strong orange-red-emitting materials for luminescence lifetime thermometry,anti-counterfeiting,and solid-state lighting applications

Strong orange-red-emitting Ba₂LaTaO₆:Eu³⁺ phosphors were designed and applied in various optical applications of luminescence lifetime thermometer, anti-counterfeiting film, and solid-state lighting applications. The crystal structure, elemental composition, asymmetry ratio, and other luminescent behaviors were investigated in detail. Especially, the optimal Ba₂LaTaO₆:0.1Eu³⁺ phosphor presented remarkable quantum yield (45.29%) and thermal stability (71.52% at 423 K). Based on the temperature-dependent luminescence decay curves, the maximum relative sensing sensitivity was 0.185 × 10^?2 K^?1 at 513 K. In addition, a novel anti-counterfeiting technique was introduced. The fabricated polydimethylsiloxane films exhibited three different colors under the irradiations of room light, 254 nm light, and 365 nm light, respectively. Eventually, the packaged light-emitting diode displayed the pure orange-red emission. Briefly, a series of the Eu³⁺-activated Ba₂LaTaO₆ phosphors with excellent luminescent properties were characterized and further applied in several optical fields for the first time.