Study Of High Performance Phosphor-in-glass Design And Laser Lighting Characteristics For Automotive Headlights

The laser headlamp for automobile headlamp based on laser diode（LD）has the advantages of strong directivity,high optical power density,etc.It can not only increase the projection distance and improve the safety,but also has smaller volume and more compact structure.It is expected to become a new generation of automobile lighting source,with important scientific and application value.Fluorescent conversion material is the key core material of automobile headlamp,and its performance directly determines the light conversion efficiency and light color quality of headlamp.In order to overcome the problems of low thermal conductivity,poor heat resistance,easy aging and yellowing,carbonization and blackening of existing organic resin packaging materials,a series of phosphor-in-glass（film）with high luminous efficiency,high thermal stability and high color rendering index were prepared by pressing sintering method and scraping coating method using all inorganic tellurite phosphor-in-glass（film）as fluorescence conversion materials.The main work and achievements of this paper are as follows:（1）In view of the problem that low melting point tellurite matrix glass is easy to corrode the crystal of phosphor powder,by abandoning low valence and small radius metal ions such as Li⁺,Na⁺,K⁺,Mg²⁺,Ca²⁺,Zn²⁺,etc.,and introducing high valence and large radius oxides such as Ge O₂,Gd₂O₃,and Ga₂O₃,the matrix glass components and network structure were designed and optimized,and the low-loss composite with YAG:Ce yellow fluorescent powder was successfully carried out,so that the crystal structure of phosphor powder was effectively protected,A highly efficient yellow phosphor-in-glass was obtained,with the maximum luminous efficiency of 230 lm/W;（2）Aiming at the problems of poor thermal stability of YAG:Ce yellow phosphor and insufficient green light composition,it is proposed to replace YAG:Ce yellow phosphor with Lu AG:Ce green phosphor with excellent thermal stability,and successfully composite with tellurite matrix glass to obtain a green phosphor-in-glass with high luminous efficiency and excellent thermal stability.When the sample temperature is 200℃,its emission intensity can still maintain 87.5%of that at room temperature;（3）Aiming at the problems of insufficient phosphor red light composition of YAG:Ce and Lu AG:Ce,and low fluorescence saturation threshold and low color rendering index of laser lighting source,a series of high-quality phosphor-in-glass films for laser lighting were obtained by simultaneously introducing Ca Al Si N₃:Eu²⁺red phosphor into the phosphor-in-glass films by scraping and coating,with the color rendering index up to 85.Through this research,a series of high-performance phosphor-in-glass（films）have been obtained.On this basis,further research on the fluorescence saturation threshold and laser irradiation resistance of this material can be carried out,making it widely used in the field of automobile headlamp.