Study Of Fabrication And Performance Of New-type YAG Luminescent Material For LED

As the fourth-generation lighting source,WLED possess the merits of low energy-consumption,high luminescence efficiency,etc.The most widely used realization method of WLED is combining YAG:Ce phosphor and GaN blue chip.Phosphor is the most fundamental material and its performance will directly decide the packaged LED quality.Unsteady PL property could occur resulting from deliquesce and grain crushing.Heat and blue light erosion in laminated packaging inevitably causes device light decay.Therefore,it is necessary to develop a kind of material carrier with good thermal stability and tunable chromaticity,as well as supporting remote-type packaging.In order to solve above-mentioned problems,this thesis focuses on fabricating YAG phosphor with high porosity,incorporating Si⁴⁺-N^3-bond into garnet and slightly adjusting Y-Al ratio in YAG to regulate PL spectrum.YAG:Ce luminescent ceramic was fabricated by aqueous tape casting with excellent thermal stability,CASN₃:Eu²⁺film was stacked onto borate luminescent glass for the purpose of high power usage and tunable chromaticity.The main conclusions are as follows:?1?Pure high-porosity YAG:Ce phosphor has been synthesized with the singtering flux of 1 wt%H₃BO₃,1 wt%NaF,0.5 wt%CaCO₃,1 wt%CMC,and sintering temperature of 1450?.Particle size reaches 25.65?m after 8 h sintering time.?2?The lattice paremeter shrinked and the PL spectrum moved towards longer wavelength direction by 8.2 nm after the introduction of Si⁴⁺-N^3-bond in YAG:Ce,SiN phosphor,the best Si₃N₄ addition amount and Y-Al ratio were 0.25 atm%,0.55,respectively.?3?The addition of 0.8 wt%PAA and 10 wt%PVA-1788 improve the rheological property of aqueous slurry,then the cast tapes were sintered to form YAG:Ce luminescent ceramic film,whitch was demonstrated performing excellent thermal stability.?4?Chromaticity-tunable color-converter material was fabricated by tape casting CASN₃:Eu²⁺red film layer onto YAG:Ce³⁺borate PiG,the laminated device has tunable chromaticity and D_uv are less than 0.0060,the PL intensity under 200?remained 85%compared with room temperature.Optical coupling also exist between them.