NaYF_(4):Yb^(3+)/Er^(3+)/Tm^(3+)纳米晶的温度传感特性研究

Temperature Sensing Performance of NaYF_(4):Yb^(3+)/Er^(3+)/Tm^(3+)Nano-Crystals

采用水热法制备了NaYF_(4):Yb^(3+)/Er^(3+)/Tm^(3+)纳米晶,对样品的晶体结构、微观形貌、上转换发射光谱及温度传感特性进行了研究。结果表明,样品为六方相,由类球状纳米晶组成,分散性较好。在980 nm激光激发下,样品表现出上转换发光,发射峰分别对应于Er^(3+)和Tm^(3+)离子的特征能级跃迁。基于荧光强度比技术,在293~573 K温度范围内,研究了样品基于热耦合能级和非热耦合能级的温度传感性能。发现该样品具有5个性能优异的耦合能级,最大绝对灵敏度S_(A)和相对灵敏度S_(R)分别为0.2974 K^(-1)和1.174%∙K^(-1)。此外,各耦合能级最大灵敏度的温度区间不同,赋予材料在更宽的温度范围具有高灵敏度,且多个耦合能级同时作用,能进一步提高测温精度。实验结果表明该样品在光学测温领域具有较好的潜在应用价值,本研究同时也为开发其他高性能光学温度传感材料提供了新的思路。

The NaYF_(4):Yb^(3+)/Er^(3+)/Tm^(3+)nano-crystals were synthesized via a hydrothermal method.The crystal structure,micro-morphology,up-conversion luminescence and temperature sensing performance of the sample were investigated by X-ray diffraction,field emission scanning electron microscope and photoluminescence spec⁃trometer,respectively.The results showed that the sample has a pure hexagonal phase,and is composed of spherical-like nano-crystals with good dispersivity.Under 980 nm laser excitation,the sample exhibits up-con⁃version luminescence,and the emission peaks are corresponded to the characteristic transitions of Er^(3+)and Tm^(3+)ions,respectively.Based on the fluorescence intensity ratio technique,the temperature sensing property of the sample was investigated systematically based on both thermal and non-thermal coupling levels in temperature range of 293~573 K.The results indicated that the sample exhibits five excellent coupling energy levels.The maximum absolute sensitivity S_(A) and relative sensitivity S_(R) reach 0.2974 K^(-1)and 1.174%·K^(-1),respectively.Fur⁃thermore,the maximum sensitivity for various coupling energy levels appears at different temperatures,which endowing the material high sensitivity in a quite wider temperature range.And the accuracy of temperature mea⁃surement could be further improved when a dual-modal temperature sensing is realized.The results imply that the presented material has a good potential application prospect in the field of optical thermometer,and the present strategy will provide a thought for developing other innovative optical temperature sensing materials with high performance.