Ratiometric luminescence thermometry is awfully applicable for non-contact temperature detection. Lanthanide luminescent materials available for high-performance ratiometric thermometry are still highly desirable until now. Herein, two novel upconversion phosphors, Yb³⁺/Ho³⁺ co-doped BiOF and BiF₃ microcrystals, were synthesized and investigated systematically in terms of their crystalline structure, room temperature and temperature-dependent upconversion properties. Under 980 nm laser excitation, both microcrystals bring forth the characteristic emissions of Ho³⁺, with an identical overall luminescent color of green, while the intensity is much higher in BiF₃:Yb/Ho microcrystals. When increasing temperature, the upconversion intensity at various wavelengths for both microcrystals is reduced, meanwhile fluorescence intensity ratios of both 545/656 nm and 752/656 nm decrease highly regularly, establishing a ratiometric thermometry therefore. BiF₃:Yb/Ho microcrystals were demonstrated to have significantly superior thermometric performance than BiOF:Yb/Ho, and a high relative sensitivity up to 5.41% K⁻¹ as well as a wide temperature sensing range of 298–673 K were obtained.

比率发光测温法非常适用于非接触式温度检测。迄今为止，可用于高性能比率测温的镧系元素发光材料仍然非常受欢迎。在此，合成了两种新型上转换荧光粉 Yb ³⁺ /Ho ³⁺共掺杂 BiOF 和 BiF ₃微晶，并系统地研究了它们的晶体结构、室温和温度相关的上转换性能。在 980 nm 激光激发下，两种微晶均产生 Ho ³⁺的特征发射，具有相同的整体绿色发光颜色，而 BiF _{3的强度要高得多}:Yb/Ho 微晶。当温度升高时，两种微晶在不同波长下的上转换强度都降低，同时545/656 nm和752/656 nm的荧光强度比高度有规律地降低，因此建立了比例测温法。BiF ₃ :Yb/Ho 微晶被证明具有明显优于 BiOF:Yb/Ho 的测温性能，并且获得了高达 5.41% K ^-1的高相对灵敏度以及 298–673 K 的宽温度传感范围。