基于BaMgSiO_(4)氧空位缺陷发光的可视化荧光温度传感材料

温度是表征物理化学性质的最基本参数之一,精确的温度测量对于现代科学技术发展起着至关重要的作用。传统基于稀土离子热耦合能级对(TCLs)能量传递的荧光温度传感器因TCLs之间能量差的限制存在测温灵敏度低及信号区分困难等问题。为寻求更优的解决方案,本研究探索了氧空位缺陷发光在荧光温度传感器领域的应用前景。本文通过高温固相法合成了BaMgSiO_(4)陶瓷,由于在高温烧结过程中有少量Ba^(2+)和Mg^(2+)蒸发,陶瓷中会产生氧空位以保持材料电中性。这些氧空位所形成的缺陷能级在332 nm紫外光激发下,发射出372,400,527 nm三种波长的发射光。这三种发射光强度对温度有着不同的敏感性,使得其能够良好应用于荧光温度传感领域。其中,I372和I527组成的温度传感系统相对测温灵敏度在298 K时为2.90%·K^(-1),高于传统TCLs荧光温度传感器的测温灵敏度,突破了TCLs温度传感器的灵敏度天花板。另外,由于372 nm和527 nm波长相差较大,使得BaMgSiO_(4)陶瓷有着室温下绿光发射到458 K高温下蓝光发射的显著变化,实现了温度监控可视化。因此,BaMgSiO_(4)陶瓷因其独特的氧空位缺陷发光特性,为开发荧光温度传感器提供了一种高精度和可视化的新选择,为荧光温度探测技术提供了一条新思路。

示温漆颜色温度特性分析与温度识别系统

比较系统地分析了示温漆的颜色温度特性 ,提出了几种温度识别方法。通过试验分析了不同方法的差别 ,以及不同颜色空间对温度识别准确性的影响 。

水热法制备Sr_(2)LuF_(7):Ln^(3+)(Ln=Yb,Er,Ho)荧光粉及其温敏性能探究

利用无模板水热法成功合成出Sr_(2)LuF_(7):Ln^(3+)/Ho^(3+)/Er^(3+)等一系列荧光粉,不断调节掺杂离子的浓度,得到基于Sr_(2)LuF_(7)基质中的最佳掺杂浓度比为20%Yb^(3+),3%Ho^(3+),并出现了浓度猝灭现象,由此可判断Yb^(3+)/Ho^(3+)之间存在能量传递。通过改变泵浦功率的大小,发现在980 nm光源激发下Sr_(2)LuF_(7):Ln^(3+)/Ho^(3+)荧光粉的发光过程为双光子过程,并分析了Yb^(3+)/Ho^(3+)之间可能的能量传递过程。最后研究了在323~523 K温度区间内,Sr_(2)LuF_(7):20%Yb^(3+),3%Er^(3+)荧光粉的温度传感性能,基于2H 11/2和4S 3/2这两个热耦合能级计算出荧光强度比(FIR),FIR对温度的依赖性,随着温度的升高,FIR不断减小。随后利用荧光强度比与温度的依赖关系计算了材料的相对灵敏度,得出在323 K时达到最大灵敏度,为1.016%K-1,可以认为Sr_(2)LuF_(7):20%Yb^(3+),3%Er^(3+)是一种有前途的温度传感材料。

Ruby (Al_2O_3∶Cr^(3+)) Fluorescence Thermometer Using PLD-PMSR Technique

A kind of fluorescence fiber-optic thermometer is devised based on the solid-state ruby fluorescence material. The characteristics of fluorescence material absorption and emission are analyzed, and the fiber-optic temperature measurement probe in ruby is developed. This system is particularly adaptable to the temperature measurement in the range of 20℃ to 600℃. During the experiment, this method is proved to be useful to temperature measurement with high resolution and precision.

Non-stoichiometry in Ca2Al2SiO7 enabling mixedvalent europium toward ratiometric temperature sensing

Eu^2+/Eu^3+ mixed-valence couple co-doped material holds great potential for ratiometric temperature sensing owing to its different electronic configurations and electron-lattice interaction. Here, the correlation of nonstoichiometry in chemical composition, phase structures and luminescence propertis of Ca2 Al2 Si1-xO7:Eu is discussed, and controlled Eu^2+/Eu^3+ valence and tunable emission appear with decreasing Si content. It is found that the 2 Ca^2++ Si^4+←→ Eu^2++ Eu^3++ Al^3+ cosubstitution accounts for the structural stability and charge balance mechanism. Benefiting from the diverse thermal dependent emission behaviors of Eu^2+ and Eu^3+, Ca2 Al2 Si1-xO7:Eu thermometer exhibits excellent temperature sensing performances with the maximum absolute and relative sensitivity being 0.024 K-1(at 303 K) and 2.46% K-1(at 443 K) and good signal discriminability. We propose that the emission quenching of Eu^2+ is ascribed to 5 d electrons depopulation through Eu^2+/Eu^3+ intervalence charge transfer state, while the quenching of Eu^3+ comes from multiphonon relaxation. Our work demonstrates the potential of Ca2 Al2 Si1-xO7:Eu for noncontact optical thermometry, and also highlights mixed-valence europium-containing compounds toward temperature sensing.

An integrated flexible multifunctional sensing system for simultaneous monitoring of environment signals

With the rapid development of portable devices and internet of things,the requirement of system wearability and integration accelerates the investigation of flexible multifunctional sensors.In this study,we developed an integrated flexible sensing system with four nanowire-based sensors and a Ni microwire-based temperature sensor.The four nanowirebased sensors are three kinds of photodetectors responding to lights with different wavelengths and a gas sensor.Due to the large surface volume ratio and considerable sub wavelength effect,all the nanowire-based sensors show good sensing response and excellent linear relationship between sensitivity and temperature.The as-fabricated flexible sensing system can simultaneously detect environmental parameters,including temperature change,light intensities from UV-Visible to near infrared regions,and harmful gas concentration.Our flexible multifunctional sensing system therefore opens up a new way for the emerging portable and wearable electronics.