The Research Of Dual-emission Fluorescent Materials On The Luminescence Characteristics And Temperature Characteristics Based On The Fluorescence Intensity Ratio

Non-contact optical temperature measurement based on various optical properties of fluorescent materials can overcome the shortcomings of traditional thermometers and is considered to be a new and promising temperature measurement method.Among them,the temperature measurement technology based on fluorescence intensity ratio and fluorescence lifetime has become a research hotspot in the field of optical temperature measurement.In recent years,double perovskite structure materials have been widely used in the field of lighting because of their stable structure and diverse substitution sites.However,the potential of double perovskite-based materials in the field of temperature measurement has been rarely studied.Therefore,in this paper,a series of phosphors doped with luminescent ions using double perovskite as the host were designed,and their temperature measurement capabilities were investigated by a series of experiments.In addition,by studying the mixed-phase aluminate phosphor,the influence of energy transfer was excluded,and the influence of crystal structure and electron traps on the temperature-sensitive properties of the material was deeply analyzed,which further improved the temperature measurement sensitivity.Three kinds of phosphors,CaLa Mg Ta O₆:Bi³⁺,M(M=Eu³⁺,Sm³⁺and Mn⁴⁺),were synthesized by high temperature solid-phase method,and their crystal structures and optical properties were studied.The substitution trends and luminescence properties changes of Bi³⁺in this host with different doping concentrations were discussed in depth.In a certain temperature range,the emission spectra at different temperatures were obtained by a thermal analysis system,and the absolute sensitivity（S_a）and relative sensitivity（S_r）of the three phosphors based on fluorescence intensity ratio（FIR）were calculated.By comparison,the temperature-dependent differences of rare earth ions and transition metals in this matrix were explored.The S_a and S_r of CaLa Mg Ta O₆:Bi³⁺,Eu³⁺reached the maximum values at 573 K and 483 K,which were 0.013 K^-1 and 1.33%K^-1,respectively.However,the S_a and S_r of CaLa Mg Ta O₆:Bi³⁺,Sm³⁺reach their maximum values at 573 K and 443 K,which are0.0051 K^-1 and 1.32%K^-1,respectively.Finally,the S_a and S_r of CaLa Mg Ta O₆:Bi³⁺,Mn⁴⁺reach the maximum values of 0.094 K^-1 and 1.14%K^-1 at 573 K and 403 K,respectively.Ba Al₁₂O₁₉:Sm²⁺/Sr Al₁₂O₁₉:Sm³⁺mixed-phase phosphors were synthesized by one-step high-temperature solid-phase method,and the effect of the crystal structure difference of the two aluminates on the valence state of doping ions was investigated.The regulation of the ratio of different valence states of dopant ions can be achieved by adjusting the ratio of matrix components.The temperature-variable emission spectra in the range of 313 K to 513 K were obtained by spectrometers and heating systems,the influence of the existence of electron traps on the temperature-sensitive properties of the material was analyzed,and S_a and S_r based on FIR and fluorescence decay lifetimes were calculated.The experimental calculation shows that its FIR-based S_a-FIR and S_r-FIR reach their maximum values at 513 K and 453 K,which are 0.55 K^-1 and 2.47%K^-1,respectively.In addition,under the fluorescence lifetime based on Sm²⁺,S_a-Lifetime and S_r-Lifetime reached the maximum value of 0.046 K^-1 and3.10%K^-1 at 413 K and 473 K,respectively.Through the research on the above fluorescent materials,we found that they all have good temperature sensitivity,can be used in optical thermometers well,and have excellent application potential in the field of optical temperature measurement.