Research On 3D Printing High Power White Light LED Color Converter

As one of the key materials in solid-state lighting technology,color converters can effectively solve the problems of aging,yellowing,and color drift of existing silicone resin-encapsulated LEDs due to its high stability and excellent light-emitting performance.One of the important research directions of brightness white LED and laser lighting conversion materials.However,due to the poor physical and chemical stability of transparent organic materials and low thermal conductivity,the traditional"phosphor+resin" type color converters currently used on a large scale are used in the high-power lighting process based on high-power blue LEDs or laser diodes(LD).A large amount of heat will be generated in the luminaire,which will cause problems such as aging and yellowing of the lighting device and deterioration of thermal stability.In addition,traditional sintering technology is difficult to achieve mass production of fluorescent glass with complex three-dimensional structure,and optimized three-dimensional structure is very important for achieving high external quantum efficiency and highly integrated devices.In addition,using only monochromatic phosphors as color converters in the glass will result in the lack of red-light spectrum in the emission spectrum,and it is difficult to obtain white light with high color rendering index and good quality(CRI<70).Therefore,there is an urgent need to develop an inorganic color converter with high thermal stability and high luminous efficiency to be suitable for high-power,high-brightness white LED and laser lighting fields.In response to the above problems,this article uses nano fumed silica with a large specific surface area and commercial phosphors as raw materials,uses quartz glass light curing technology and pressureless sintering technology to prepare high-performance fluorescent glass,and on this basis,it is combined with 3D printing technology.Combined,successfully prepared fluorescent glass with complex three-dimensional structure that is difficult to manufacture by traditional sintering technology.Finally,in order to further improve the light conversion efficiency and color rendering performance of the lighting device,we coated the red phosphor CaAlSiN3:Eu2+on the LuAG:Ce-PiSG fluorescent glass to obtain a color converter with high color rendering index and high lumen efficiency.The main contents of this paper are as follows:(1)Preparation and performance research of YAG:Ce color converterIn view of the traditional "phosphor+resin" type color converters in high-power lighting,there are aging and yellowing,thermal stability deterioration,and traditional sintering technology is difficult to achieve the manufacture of color converters with complex three-dimensional structure.This chapter will focus on the combination of glass light curing molding technology and pressureless sintering technology,which successfully sintered at a high temperature of 1250℃ to produce YAG:Ce-PiSG fluorescent glass with high thermal stability and excellent luminescence performance.The phosphor powder is uniformly distributed in the glass matrix,and the microscopic morphology and crystal structure are destroyed,which greatly protects the luminescence performance of the fluorescent glass.In addition,by combining modern 3D printing technology,we directly design and manufacture traditional sintering technology that is difficult to achieve YAG:Ce-PiSG fluorescent glass with a more complex three-dimensional structure.Subsequently,we applied the prepared YAG:Ce-PiSG to white light LED and laser lighting.The maximum output lumen of the white light LED device is 7851m and the maximum luminous efficiency is 1191m/W;the maximum output laser power of the white light laser lighting device is 2.72W(3.46W mm-2).These results indicate that the color converters prepared in this article has excellent luminescence performance and high thermal stability,and has shown great application potential in the fields of high-power and high-brightness white LED lighting and laser lighting.(2)red powder composite LuAG:Ce-PiSG preparation and performance researchAiming at the problem that monochromatic phosphors are used as color converters in glass,resulting in the lack of red-light spectrum in the luminescence spectrum,it is difficult to obtain white light with high color rendering index and good quality.We have prepared LuAG:Ce-PiSG with high stability and excellent luminescence performance.The phosphor powder is uniformly distributed in the glass matrix,and the microscopic morphology and crystal structure are destroyed,which greatly protects the luminescence performance of the fluorescent glass.Later,we applied it to laser lighting.The maximum output lumens of the white light lighting device were 5621m and the maximum luminous efficiency was 1021m/W.Finally,we coated the red phosphor Ca2S15Al8:Eu2+ on LuAG:Ce-PiSG fluorescent glass and applied it in laser illumination.The results show that the color rendering index(92)and luminous efficiency of white light lighting devices have been significantly improved.