Abstract Ho3+/Ce3+ co-doped K2YbF5 microcrystals were synthesized by solvent-thermal method. Under excitation of 980 nm laser diode, effectively visible and 2 μm-infrared luminescence of Ho3+ ion were obtained in the microcrystals. By changing Ce3+-ion doping concentration, the luminescence properties of visible and 2 μm emission were effectively regulated. At low Ce3+-ion doping level, the red and green upconversion emission obviously increases and decreases respectively with the increase of Ce3+-ion amount in the samples, meanwhile the intensity of 2 μm fluorescence changes very little. At high Ce3+-ion doping level, the intensities of the red and green emission both decrease with the increase of Ce3+-ion concentration, while the 2 μm emission intensity increases obviously. In the sample doped with 16% Ce3+ ion, the intensity of 2 μm emission is about 4.5 times that of the sample without Ce3+ ion, and the corresponding quantum efficiency is about 78.3%. The result is attributed to the influence of the different cross relaxation between Ho3+ and Ce3+ ion in luminescence process at low and high Ce3+-ion doping concentration. The corresponding luminescence mechanism and energy transfer process were discussed in detail.

中文翻译：

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K2YbF5：Ce3+/Ho3+ 微晶中的高效可见光和 2 μm 红外发射

摘要 采用溶剂-热法合成了Ho3+/Ce3+共掺杂K2YbF5微晶。在 980 nm 激光二极管的激发下，在微晶中获得了有效的可见光和 2 μm 红外发光的 Ho3+ 离子。通过改变Ce3+离子掺杂浓度，可以有效调节可见光和2 μm发射的发光特性。在低Ce3+离子掺杂水平下，红色和绿色上转换发射分别随着样品中Ce3+离子量的增加而明显增加和减少，同时2 μm荧光强度变化很小。在高Ce3+离子掺杂水平下，红色和绿色发射强度均随着Ce3+-离子浓度的增加而降低，而2 μm发射强度明显增加。在掺杂 16% Ce3+ 离子的样品中，2 μm发射强度约为不含Ce3+离子样品的4.5倍，相应的量子效率约为78.3%。结果归因于在低和高Ce3+-离子掺杂浓度下发光过程中Ho3+和Ce3+离子之间不同的交叉弛豫的影响。详细讨论了相应的发光机理和能量转移过程。