Synthesis And Luminescent Properties Of Er³⁺/Yb³⁺/Zn²⁺ Doped C12A7Polycrystal

For a country even the whole world, the economy and technologicaldevelopment are based on the material. The rapid expansion of industrial andeconomic, leads to the research and application on traditional materials havemade great achievements. On one hand, the traditional material in nature reservesare limited; On the other hand, the performance requirements of modern hightechnology is higher and higher, which result in the limited usage of traditionalmaterials. So we must look for new materials with special properties and specialpurpose. Many new functional materials and cutting-edge technology beenwidely studied and applied are benefited from the quickly change and continuousimprovement of science and technology. The upconversion technology removesaway the bottleneck for the study, development and utilization of materials. Inthe article,12CaO·7Al2O3(C12A7) is selected as the matrix material based on theadvantages of its various aspects. The material not only has the advantage of highluminous efficiency but also owns the overall performance of light transmittanceand conductivity.Material synthesized by different process may share the same properties andmay also have different characteristics. The method of respectively fixedsintering time and change sintering temperature and fixed sintering temperatureand change sintering temperature is used to determine the sintering temperatureand sintering time of high temperature solid state method being utilized topreparation C12A7doped with rare earth ions. Three groups C12A7sampleswith different Er3+, Yb3+and Zn2+ions concentrations are prepared in a high-temperature resistance furnace with the process, of which the aim is to explorethe upconversion luminescent properties of C12A7polycrystal doped withdifferent rare earth elements and Zn2+ion. The samples are tested by XRD, fluorescence spectroscopy, the pump powerdependence, UV-visible absorption edge testing and time-resolved spectroscopy.The testing results can be used to speculated upconversion luminescenceproperties, upconversion luminescence mechanism, ions occupying situationinside the crystal. The three groups of samples emit530nm and549nmupconversion green light and664nm upconversion red light when they areirradiated by980nm diode laser, respectively corresponding to the three leveltransition of Er3+ions, they are2H11/2â†'4I15/2,4S3/2â†'4I15/2and4F9/2â†'4I15/2. Thefluorescence are based on a two or three photons process. In addition, the UV-visible absorption edge of samples appeared small offset. What’s more, themechanism of upconversion luminescence is also elaborate in the paper.