Study On Synthesis And Upconversion Properties Of Zn/Yb/Tm/C12A7 Polycrystalline

The new energy era is coming,the upconversion materials become a new hot topic.Lanthanide-doped C12A7 have been found a number of promising properties such as electrical property,upconversin optical property,which leads to a broad application.In this paper,high temperature solid-state method was used to synthetic Zn²⁺/Yb3+/Tm3+/C12A7 material.And then optimize process parameters by the XRD analysis,TG-DSC analysis and upconversion emission analysis.Under the condition of optimum process,Zn²⁺/Yb3+/Tm3+/C12A7 polycrystalline materials with different doping concentration were prepared.The highest phonon energy of C12A7 detected by Raman spectroscopy was 778 cm-1,which made C12A7 material suitable for upconversion luminescence.In addition,the influence of Zn²⁺ ion on C12A7 crystal structure has been studied via the XRD analysis,uv–visible absorption analysis and infrared-visible absorption analysis.In order to investigate factors affecting upconversion emission,the research emphasis on the effect of Yb3+ ions,Tm3+ ions and Zn²⁺ ions.An orthogonal test of three factors at four levels has been designed to obtain the optimum concentration.And then design an orthogonal test of three factors at four levels to obtain the best solution.The photon process of upconversion luminescence was systematically studied by changing pump powers.It is concluded that three-photon processes are involved to generate the blue and red upconversion emission.Combined with the Yb3+ ions and Tm3+ ion energy level transition spectra,analyzed the mechanism of fluorescence of doping system deeply.The upconversion fluorescence mechanism doping with Zn²⁺ ion was analyzed by the fluorescence lifetime.The decay dynamics of emission generated at 475 nm,650 nm and 980 nm were measured to calculate fluorescence lifetime.The results show that the doping Zn²⁺ ion can enhance upconversion intensity owing to the change of fluorescence lifetime.The pump power and temperature are used to control the upconversion intensity and fluorescence photochromic via CIE analysis,which paves a way for application in the area of 3D display.Meanwhile,the intensity of 3F2,3 and 3H4 states under different temperature are measured to calculate FIR value.After linear fitting,the final slope corresponding to temperature sensibility coefficient is 1901/T2,leading a potential application in temperature sensor.