Cost Optimization Optimization And Spectral Control Of Ba₉Lu₂Si₆O₂₄:Ce³⁺ Cyan Phosphor For White LED

White LED has the advantages of energy saving,environmental protection,high efficiency,long life and stability,which is widely used in the current lighting field.At present,the blue LED chip and yellow powder are widely used in the market to realize the white LED.which has some problems such as high color temperature,poor color rendering index and color drift caused by the influence of blue chip.Therefore,the ultraviolet LED and three basic color phosphors can adjust the color temperature by adjusting the proportion of different phosphors because of their uniform spectral composition,high color rendering index and not affected by the current at present,it is the best WLED solution.For UV excited WLED,phosphors emitting blue and green light are essential.At present,many blue and green phosphors have narrow half height and width,which will cause spectral vacancy between the blue and green spectra,so it is very necessary to develop a cyan phosphor that can fill the spectral vacancy;secondly,if we can develop a broadband cyan phosphor that can cover the blue and green,we can avoid mixing the tricolor phosphors to a large extent Reabsorption in the process.Ba₉Lu_1.5Al_0.5Si₆O₂₄:Ce³⁺(BLS:Ce³⁺)cyan phosphor is a kind of UV excited phosphor with superior performance at present.It has the characteristics of high quantum efficiency,good thermal stability,wide half height and width,and simple preparation.The white LED phosphor with high color rendering index can be obtained by doping the simple red phosphor.However,due to the high price of rare earth element Lu,its cost is high.In order to improve its competitiveness,it is of great significance to optimize the cost and performance of raw materials.The specific research contents are as follows:（1）Ba₉Lu_1.5Al_0.5Si₆O₂₄:Ce³⁺(BLASO:Ce³⁺)cyan phosphor was obtained by replacing Lu₂O₃in the raw material with cheaper Al₂O₃.Under 400 nm excitation,BLASO:Ce³⁺shows a emission peak at 488 nm with an FWHM of about 117 nm.At room temperature,the internal quantum efficiency（IQE）can reach as high as 90.8%.At 150°C,the IQE decreases to 81.5%,indicating an excellent thermal stability.The effect of the Al substitution for Lu on crystal structures and photoluminescence were investigated.The homogeneity of the luminescence was diagnosed by viewing microscopic particles based on the scanning electron microscope（SEM）equipped a cathodoluminescence（CL）system.（2）Ba₉Lu_1.5Ga_0.5Si₆O₂₄:Ce³⁺(BLGSO:Ce³⁺)blue phosphor was obtained by replacing Lu₂O₃in the raw material with cheaper Ga₂O₃.Under 400 nm excitation,BLGSO:Ce³⁺shows an emission peak at 488 nm with a FWHM of about 125 nm.The internal quantum efficiency（IQE）excesses90%.At 200°C,the luminescence decreases to 93.7%of that at room temperature,indicating an excellent thermal stability.Combining with CaAlSiN₃:Eu²⁺and 395 nm chip,a white LED with a color rendering index of 91.9 and a correlated color temperature of 4720 K was achieved.The homogeneity of the luminescence was diagnosed by viewing microscopic particles based on the scanning electron microscope（SEM）equipped a cathodoluminescence（CL）system.（3）By optimizing the sintering process and doping BaF₂ with a small amount of cosolvent,Ba₉Lu_1.5Al_0.5Si₆O₂₄:Ce³⁺(BLASO:Ce³⁺)cyan phosphor with better performance was obtained.Under the excitation of 400 nm,the peak position of BLASO:Ce³⁺emission did not change significantly.Combined with CaAlSiN₃:Eu²⁺and 395 nm chips,a white light with color index of94.2 and related color temperature of 5034 K was realized.It shows that it has a better color rendering index.