Near-infrared (980 nm) to near-infrared (800 nm) and blue (490 nm) upconversion has been studied in 0.2% Tm³⁺ and 10% Yb³⁺ codoped Lu₂O₃–ZrO₂ solid solutions as a function of the ZrO₂ content in the range of 0–50%, prepared by a high-temperature solid-state reaction. The continuous enhancement of upconversion luminescence is observed with increasing ZrO₂ content up to 30%. Analyses of the Yb³⁺ emission intensity and lifetime indicate enlarged absorption of a 980 nm excitation laser and enhanced energy transfer from Yb³⁺ to Tm³⁺ with the addition of ZrO₂. The spectrally inhomogeneous broadening of the dopants in this disordered solid solution is considered to play the main role in the enhancement by providing better matches with the excitation laser line and increasing the spectral overlap for efficient energy transfer from Yb³⁺ to Tm³⁺. In addition, the inhomogeneous broadening is also validated to improve energy migration among Yb³⁺ ions and energy back transfer from Tm³⁺ to Yb³⁺. Hence, it is understandable that a drop in the upconversion luminescence intensity occurs as the concentration of ZrO₂ is further increased from 30% to 50%. This work indicates the possibility of disordered crystals to achieve intense upconversion luminescence for biological and optoelectronic applications.

中文翻译：

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Tm ³⁺和Yb ³⁺共掺杂Lu ₂ O ₃ –ZrO ₂无序晶体中的不均匀增宽诱导的强烈上转换发光

在0.2％Tm ³⁺和10％Yb ³⁺共掺杂Lu ₂ O ₃ –ZrO ₂固溶体中研究了近红外（980 nm）到近红外（800 nm）和蓝（490 nm）上转换通过高温固相反应制备的ZrO ₂含量为0-50％。随着ZrO ₂含量增加至30％，观察到了上转换发光的连续增强。对Yb ³⁺发射强度和寿命的分析表明，添加ZrO _2可以增加980 nm激发激光的吸收，并增强从Yb ³⁺到Tm ^3+的能量转移。。通过提供与激发激光线更好的匹配并增加光谱重叠以实现从Yb ³⁺到Tm ^3+的有效能量转移，该无序固溶体中掺杂剂的光谱不均匀扩宽被认为在增强中起主要作用。此外，还证实了不均匀加宽可以改善Yb ³⁺离子之间的能量迁移以及能量从Tm ³⁺向Yb ^3+的反向转移。因此，可以理解的是，随着ZrO ₂的浓度，上转换发光强度下降。从30％进一步增加到50％。这项工作表明无序晶体有可能实现用于生物和光电应用的强烈的上转换发光。