Study On The Temperature Sensing Characteristics Of Yb³⁺/Er³⁺ Co-doped Gd₂?MoO₄?₃/NaLuF₄ Fluorescent Materials

In recent years,researchers have conducted in-depth studies on optical temperature sensing based on upconversion fluorescence materials,but there are still some problems such as low sensitivity and large measurement error.Molybdate as inorganic compounds with a lower phonon energy,good chemical stability and high quantity,make its can be applied to the temperature sensing superiority transformation of luminescent materials.In addition,many researchers have been working hard to achieve high precision temperature sensing and improve the sensitivity of optical temperature sensing.The main research of this paper is as follows:Gd2(MoO4)3:Yb3+/Er3+ phosphors were synthesized by means of sol-gel method by controlling calcination temperature and calcination time,respectively.The effect of calcination temperature on the phase of samples was studied.Excited by a 980 nm laser,the sample showed stronger green light and weaker red light.In addition,the relationship between the phase structure the samples and the luminescence spectra as well as the calcination time under the calcination temperature of 630 and 800 ? were researched,respectively.The results showed that the calcination time on samples had no effect on the phase structure and photoluminescence spectrum under the calcination temperature 800 ?.Under 980 nm excitation,the effect of temperature on the upconversion luminescence of monoclinic phase Gd2(MoO4)3:Yb3+/Er3+ phosphors was studied,and the mechanism of the fluorescence intensity of the samples related to temperature was described.By studing the temperature sensing characteristics of the samples,it is found that Gd2(MoO4)3: Yb3+/Er3+samples possess maximum sensitivity 0.02574 K-1 at 510.2 K,meaning that the material is high sensitivity temperature measurement of potential candidate materials.Within the temperature range of 299-482 K,the dependence of fluorescence characteristics and calcining temperature was studied in detail,and the relationship between the luminescence intensity and calcination temperature was explained.Furthermore,by studing the influence of calcining temperature on the optical temperature sensor sensitivity,it is found that the sample calcined at 700 ? achieved greatest sensitivity 0.02533 K-1at 482 K.The hexagonal NaLuF4: Yb3+/Er3+ powder was prepared by hydrothermal method.It is found that emitting light colors almost no change with increasing temperature from 296 to 461 K under 1064 nm excitation,suggesting that NaLuF4:Yb3+/Er3+powder has excellent color stability and can be applied to the imaging of under the environment of high temperature and illumination.In addition,we have designed a strategy to enhance sensitivity based on multi-phonon assisted excitation.Compared with temperature measurement based on FIR technique of TCL,a higher sensitivity is obtained to be 0.0194 K-1 using NCRT method.These meaningful results reveal that NCRT is an effective method for enhancing sensitivity in the temperature range from 296 to 420 K.