Preparation And Properties Of Tellurate Glass Doped With Phosphor

White LED,called as the fourth generation lighting source,has been widely applied in the field of indoor lighting and outdoor lighting due to its small volume,energy saving,environmental friendliness,fast response time,long life and so on.The current mainstream LED disperses phosphors in silica gel as packaging materials.However,due to the poor thermal conductivity of silica gel materials,the heat produced by LED chips can not be released rapidly.Thermal and optical radiation for a long time make silica gel materials easily aging and yellowing,which will lead to light efficiency attenuation,color temperature drift and life shortening of LED devices.In view of inorganic bulk materials such as glass and ceramics with stable physical and chemical properties and high thermal conductivity,the properties of LED devices will be greatly improved by using the luminescent materials prepared by it instead of the silica gel phosphor mixture for packaging.In this paper,Y₃Al₅O₁₂:Ce³⁺（YAG:Ce）tellurate phosphor-in-glass（PiG）with high transparency and excellent optical properties was successfully prepared by one-step low temperature co-sintering method.The Lu₃A₅O₁₂:Ce³⁺（LuAG:Ce）tellurate PiG coated with red film was prepared by one-step low temperature co-sintering method and spin-coating technique.Then,the phase structure,microstructure,optical properties,thermal stability and photoelectric properties of the prepared samples were systematically analyzed by various characterization methods.The main research results are as follows:1.YAG:Ce tellurate PiG was successfully prepared by one-step low temperature co-sintering method.The properties of YAG:Ce tellurate PiG were studied by means of transmittance,XRD,SEM,fluorescence spectrum and photoelectric performance analysis.The optimum doping concentration of phosphor and the thickness of PiG are 8 wt%and 0.8mm respectively.The luminescent efficiency（LE）of the white LED device is 102.6 lm/W,the correlated color temperature（CCT）is 6290K,the color rendering index（CRI）is 71.4,and the CIE Color coordinates is（0.3165,0.3311）.The results of temperature-dependent emission spectra show that When the temperature is 200℃,the thermal stability of PiG is better than that of phosphor-in-silicone（PiS）.2.LuAG:Ce tellurite PiG was successfully prepared by one-step low temperature co-sintering method,and then a thin and uniform CaAlSiN₃:Eu²⁺(CASN:Eu²⁺)red phosphor film was formed on the surface of PiG by spin-coating technique.The Chrominance regulation of the white LED encapsulated by PiG plate coated with red film can be realized,and the white light can be transferred from cold white light to warm white light.The optimum doping ratio of CASN:Eu²⁺phosphors and thickness of LuAG:Ce PiG are 20 wt%and 1.0mm respectively.The warm white LED device encapsulated by PiG plate coated with red film has excellent photoelectric performance.The LE is 90.65lm/W,the CCT is 3289K,the CRI is91.6,and the CIE Color coordinates is（0.4194,0.4004）.Under the optimum conditions,the large size LuAG:Ce tellurate PiG coated with red film can be encapsulated into high power chip-on-board（COB）devices and used in the field of high power LED.