Luminescence and Thermal Stability of Dy ³⁺ Doped La _0.1 Y _1.9 WO ₆ Phosphors

Abstract The La 0.1 Y 1.9‐x WO 6 : xDy 3+ ( x = 0.01–0.07) phosphors were prepared by the high‐temperature, solid‐state reaction method. The systematic characterizations include phase purity, crystal structure, luminescent properties, and thermal stability. The crystal phase is of the monoclinic ( P2/c ) system. Notably, La 0.1 Y 1.9‐x WO 6 : xDy 3+ exhibits strong scintillation luminescence under X‐ray excitation, with the luminescence intensity is strongly dependent on the Dy 3+ dopant concentration. Moreover, the phosphor demonstrates enhanced luminescence after X‐ray irradiation under ultraviolet (UV) excitation. These single‐doped La 0.1 Y 1.9‐x WO 6 : xDy 3+ phosphors can emit yellow light, and their emission chromaticity strongly depends on the Dy 3+ doping concentration. The luminescence intensity remains at 75.8% and 71.2% at room temperature when Dy 3 ⁺ concentration is 0.03 and 0.05, respectively, upon excitation at 353 and 317 nm at 150 °C. A warm‐white LED source was fabricated by combining a commercial 365 nm LED chip with the La 0.1 Y 1.87 WO 6 :0.03Dy 3+ phosphor. These new findings may enable novel applications of these materials in solid‐state lighting, radiation detection, and dosimetry.