In this work, calcium niobium gallium garnet (Ca₃Nb_1.6875Ga_3.1875O₁₂ - CNGG) ceramic samples single-doped with Tb³⁺ and co-doped with Tb³⁺ and Yb³⁺ ions were sintered by the solid-state reaction method. The structural characterization of the samples was carried out by X-ray diffraction measurements. The optimal concentration of Tb³⁺ ions corresponding to the maximum luminescence in the green spectral range in CNGG:x at% Tb (x = 0.1, 0.5, 1, 2, 3, 4, and 5) was determined to be 4 at%. The time-resolved luminescence of the ⁵D₄ level (Tb³⁺) in the CNGG:x at% Tb samples was analysed to explore the quenching mechanisms involved in the Tb³⁺ green emission. Co-doped CNGG:4 at% Tb,y at% Yb (y = 0.5, 2, 4, 6, 8, and 10) ceramics were prepared and investigated. It is shown that CNGG:4 at% Tb,y at% Yb phosphors exhibit intense green luminescence under ultra-violet (UV), visible (VIS), and near-infrared (NIR) excitation, thus demonstrating the presence of simultaneous down-conversion (DC) and up-conversion (UC) processes. The dependence of the UC luminescence intensity on the diode laser pumping power was measured and the results indicate a two-photon process based on cooperative energy transfer (CET). Under UV excitation, the lifetime of the ⁵D₄ (Tb³⁺) level slowly increases with increase of Yb³⁺ concentration, suggesting the energy transfer from Yb³⁺ to Tb³⁺ ions, while under NIR excitation, the lifetime of the ⁵D₄ (Tb³⁺) level decreases with increase of Yb³⁺ ions concentration, indicating the presence of a strong energy transfer from Tb³⁺ to Yb³⁺ ions. The highest energy transfer efficiency of η_ET ≈42% was determined for the CNGG:4 at% Tb,10 at% Yb sample. The obtained results indicate that CNGG:(Tb³⁺, Yb³⁺) could be efficient new yellowish-green-emitting phosphors.

本工作采用固相反应烧结单掺杂Tb ³⁺和共掺杂Tb ³⁺和Yb ^{3+离子的钙铌镓石榴石（Ca} ₃ Nb _1.6875 Ga _3.1875 O ₁₂ - CNGG）陶瓷样品。方法。样品的结构表征通过 X 射线衍射测量进行。^{Tb 3+}离子的最佳浓度对应于 CNGG 中绿色光谱范围内的最大发光：x at% Tb ( x  = 0.1, 0.5, 1, 2, 3, 4, 和 5) 被确定为 4 at% . ⁵ D ₄的时间分辨发光CNGG 中的水平 (Tb ^{3+ )：分析了}x at% Tb 样品以探索 Tb ³⁺绿色发射中涉及的猝灭机制。制备并研究了共掺杂 CNGG:4 at% Tb, y at% Yb ( y  = 0.5, 2, 4, 6, 8, 和 10) 陶瓷。结果表明 CNGG:4 at% Tb, yat% Yb 荧光粉在紫外 (UV)、可见光 (VIS) 和近红外 (NIR) 激发下表现出强烈的绿色发光，从而证明同时存在下转换 (DC) 和上转换 (UC) 过程. 测量了 UC 发光强度对二极管激光泵浦功率的依赖性，结果表明基于协同能量转移 (CET) 的双光子过程。在紫外激发下，⁵ D ₄ (Tb ^{3+ ) 能级的寿命随着 Yb 3+}浓度的增加而缓慢增加，表明能量从 Yb ³⁺转移到 Tb ³⁺离子，而在近红外激发下，⁵天₄ (结核病³⁺ ) 水平随着Yb ³⁺离子浓度的增加而降低，表明存在从Tb ³⁺到Yb ³⁺离子的强能量转移。CNGG:4 at% Tb,10 at% Yb 样品的最高能量传递效率为η _{ET ≈42%。}所得结果表明CNGG:(Tb ³⁺ , Yb ³⁺ ) 是一种高效的新型黄绿色荧光粉。