The trivalent dysprosium-doped yellow phosphor is an important component for realizing single-matrix white light. However, concentration quenching and thermal quenching greatly limit its application. White light phosphors, Li₃Ba₂Gd₃(WO₄)₈:Dy³⁺,Tm³⁺, with a stratified scheelite structure were prepared via a high-temperature solid-reaction. Calculated using the Kubelka–Munk model, the band gap of the host is 3.71 eV, which is suitable for near-ultraviolet white LEDs. The matrix is a highly disordered monoclinic crystal with a layered structure, which suppresses the concentration quenching effect of Dy³⁺ and achieves a relatively high doping concentration. A small amount of Tm³⁺ (3%) was co-doped with Dy³⁺ to obtain standard white light, whose CIE coordinate locates at (0.3370, 0.3213). Furthermore, the thermal quenching properties of Li₃Ba₂Gd₃(WO₄)₈:12%Dy³⁺,3%Tm³⁺ were investigated, and it was found that the intensity of the phosphor at 422 K maintains 82.52% of that at room temperature, and remained at 71.34% when the temperature increased to 472 K. The results indicate that the Li₃Ba₂Gd₃(WO₄)₈:Dy³⁺,Tm³⁺ phosphor can be a potential single-phased white-light-emitting phosphor for NUV white LEDs.

中文翻译：

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层结构抑制Dy3+发光浓度猝灭及与Tm3+配合实现单相白光荧光粉

三价镝掺杂黄色荧光粉是实现单矩阵白光的重要组成部分。然而，浓度猝灭和热猝灭极大地限制了它的应用。通过高温固相反应制备了具有层状白钨矿结构的白光荧光粉Li ₃ Ba ₂ Gd ₃ (WO ₄ ) ₈ :Dy ³⁺ ,Tm ^{3+ 。}使用 Kubelka-Munk 模型计算，主体的带隙为 3.71 eV，适用于近紫外白光 LED。基体为高度无序的单斜晶体，具有层状结构，抑制了Dy ^{3+的浓度猝灭效应}并达到较高的掺杂浓度。将少量Tm ³⁺ (3%)与Dy ³⁺共掺杂得到标准白光，其CIE坐标位于(0.3370, 0.3213)。此外，研究了 Li ₃ Ba ₂ Gd ₃ (WO ₄ ) ₈ :12%Dy ³⁺ ,3%Tm ³⁺的热猝灭特性，发现荧光粉在 422 K 的强度保持在 82.52%在室温下，当温度升高到 472 K 时保持在 71.34%。结果表明 Li ₃ Ba ₂ Gd ₃ (WO ₄ )₈ :Dy ³⁺ ,Tm ³⁺荧光粉可作为NUV白光LED的潜在单相白光发光荧光粉。