Spectroscopic properties play a significant role during the design and development of novel luminescent materials. In this work, quantum cutting (QC) luminescent materials KYF₄:Tb³⁺,Yb³⁺ phosphors were successfully synthesized by sol–gel method. The crystal structure, morphology, fluorescence spectra, and decay curves were investigated by X-ray diffractometer (XRD), scanning electron microscope (SEM) and spectrofluorometer. The Judd-Ofelt (J-O) parameters, Ω_λ (λ = 2, 4, 6), were directly derived from the emission spectra and decay curves, attributed to the transition intensities of Tb³⁺ ions were dependent on the J-O parameters. Then, the radiative and nonradiative transition rates, fluorescent branching ratios, cross-relaxation rates and lifetimes of QC luminescence were calculated based on the obtained J-O parameters. Moreover, the rate equation models of QC luminescence were established and the time-dependent population densities in excited levels of Tb³⁺ ions and Yb³⁺ ions were simulated. Finally, the dynamic processes of QC luminescence were discussed carefully and the corresponding theoretical quantum efficiency was estimated. Our studies would provide an insight into the QC luminescence and give theoretical guidance for developing novel luminescent materials.

光谱特性在新型发光材料的设计和开发过程中发挥着重要作用。在这项工作中，通过溶胶-凝胶法成功合成了量子切割（QC）发光材料KYF ₄ :Tb ³⁺ ,Yb ³⁺荧光粉。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)和分光光度计研究了晶体结构、形貌、荧光光谱和衰变曲线。Judd-Ofelt (JO) 参数 Ω _λ (λ = 2, 4, 6) 直接来自发射光谱和衰减曲线，归因于 Tb ³⁺的跃迁强度离子取决于 JO 参数。然后，根据获得的 JO 参数计算 QC 发光的辐射和非辐射跃迁率、荧光支化率、交叉弛豫率和寿命。此外，建立了QC发光的速率方程模型，并模拟了Tb ³⁺离子和Yb ³⁺离子在激发态下随时间变化的布居密度。最后，仔细讨论了QC发光的动态过程，并估计了相应的理论量子效率。我们的研究将提供对 QC 发光的深入了解，并为开发新型发光材料提供理论指导。