White light-emitting Ba_0.05Sr_0.95WO₄:Tm³⁺ Dy³⁺ phosphors

Desheng Zhu^1,2,3，Congkai Wang¹，Feng Jiang^1,2

1. School of Materials Science and Engineering,Central South University2. Light Alloy Research Institute, Central South University3. School of Physics and Optoelectronic Engineering Yangtze University

摘 要：Tm³⁺ and Dy³⁺ co-doped Ba_0.05Sr_0.95WO₄ phosphors were synthesized by a low temperature combustion method. The structures of the samples were SrWO₄ phase and were identified by X-ray diffraction. The surface topographies of Ba_0.05Sr_0.91WO₄:0.01 Tm³⁺ 0.03 Dy³⁺ were tested by scanning electron microscopy. The particles are ellipsoid, and their average diameter is approximately 0.5 μm. The emission spectra of Ba_0.05Sr_0.95WO₄:Tm³⁺ show a peak at 454 nm which belongs to the ³ H₆→¹ D₂ transition of Tm³⁺, and the optimum doping concentration of Tm³⁺ ions was 0.01. The emission spectra of Ba_0.05Sr_0.95WO₄:Dy³⁺ consist of the ⁴ F_9/2→⁶ H_13/2 dominant transition located at 573 nm, the weaker ⁴ F₍9/₂→⁶ H_15/2 transition located at 478 and 485 nm. and the weakest ⁴ F_9/2→⁶ H_11/2 transition located at660 nm, and the optimum doping concentration of Dy³⁺ ions was 0.05. A white light is achieved from Tm³⁺ and Dy³⁺ co-doped Ba_0.05Sr_0.95MoO₄ crystals excited at 352-366 nm. With the doping concentration of Tm³⁺ fixed at 0.01, the luminescence of Ba_0.05Sr_0.95MoO₄:Tm³⁺Dy³⁺ is closest to standard white-light emissions when the concentration of Dy³⁺ is 0.03; the chromaticity coordinates are（0.321,0.347）, and the color temperature is 6000 K.

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