Design Of Optical Temperature Sensing Properties Of Rare-earth Phosphors

Rare-earth doped phosphor has many unique excellent luminescent properties due to containing lanthanide elements which exist extremely rich energy structure,the adjacent heat coupling level by trivalent rare earth ions fluorescence intensity ratio provides the possibility of measuring temperature.In this paper,based on fluorescence intensity ratio technology,we design Er³⁺doped Sr_0.69La_0.31F_2.31 transparent ceramics,Er³⁺doped Ba₂CaWO₆phosphor,Er³⁺-Yb³⁺co-doped Na₂BaCa_0.89P₂O₈ phosphors,Ho³⁺-Yb³⁺co-doped Ca₉Y_0.9P₇O₂₈ phosphors for optical temperature sensing devices.The specific work is as follows:Firstly,in order to overcome the shortcoming of nano fluorine phosphors being oxidized easily at high temperature,we propose to design and use Er³⁺doped Sr_0.69La_0.31F_2.31 transparent ceramics materials to achieve light and temperature sensing.By analyzing the thermal quenching rate,fluorescence intensity ratio and relative sensitivity of three thermal coupling energy levels of ²H_11/2/⁴S_3/2,⁴F_9/2?1?/⁴F_9/2?2?,⁴F_9/2?2?/⁴F_9/2?3?,we explore the photo temperature sensing performance.A new fitting method is proposed to study the relationship between the fluorescence intensity ratio and the temperature.Secondly,proposing the idea of adjusting the optical and temperature sensing performance by adjusting the crystal field.Using Zn²⁺and Mg²⁺to regulate the luminescent crystal field of Er³⁺doped Ba₂CaWO₆ phosphor and the effect of pump power on the sensing properties of light temperature,the method of obtaining high sensitive light temperature phosphor is explored.Comparing the optical temperature sensing properties of various samples,it is found that Ba₂Ca_0.95WO₆Er_0.02Mg_0.03 phosphors are suitable for optical temperature measurement devices.Thirdly,the idea of exploring a new type of light temperature sensing phosphor through Yb³⁺sensitized Er³⁺energy transfer is proposed.Based on the Er³⁺-Yb³⁺co-doped Na₂BaCa_0.89P₂O₈ phosphors,We used ions Sr²⁺and Mg²⁺control the luminescent crystal field of Er³⁺-Yb³⁺co-doped Na₂BaCa_0.89P₂O₈ phosphors.Through the calculation of the relative sensitivity of phosphors,we find Na₂Ba_0.75CaP₂O₈Er_0.01Yb_0.1Mg_0.25 is the highest which is suitable for studying on the measurement of light temperature sensing.The last,we propose the idea of exploring a new type of light temperature sensing phosphor through Yb³⁺sensitized Ho³⁺energy transfer,the luminescent crystal fields of Ho³⁺-Yb³⁺co-doped Ca₉Y_0.9P₇O₂₈ phosphors were controlled by S^r2+,Ba²⁺and Mg²⁺.Under the excitation of 980nm,the temperature dependent luminescence properties of Ho³⁺red and green emission band were studied.We found that Ca_8.9Y_0.83P₇O₂₈Yb_0.1Ho_0.07Sr_0.1 is the suitable phosphor for optical temperature sensing phosphor based on fluorescence intensity ratio technology.