Surface modification method of fluoride luminescent material, and fluoride luminescent material prepared by method

Abstract

The invention relates to a surface modification method of a fluoride luminescent material, and the fluoride luminescent material prepared by the method. According to the invention, a matrix material AxMFy:Mn<4+> coated with an inorganic coating layer AxMFy, and an organic solution containing metal phosphate or alkoxy silane or an organic carboxylic acid substance or organic amine, and the obtainedmixed solution is subjected to evaporation drying to obtain the surface-modified fluoride luminescent material co-coated with the organic coating layer-inorganic coating layer; according to the coating method, the corrosion resistance of the fluoride fluorescent powder is remarkably improved, the luminous intensity retention rate and the quantum efficiency retention rate of the modified fluorescent powder reaches 85-95% in a high-temperature and high-humidity environment, and the fluoride fluorescent powder can be widely applied to the field of white light LED backlight source display; afterinorganic coating, the surface defects of the fluorescent powder are reduced, and the luminous intensity and the quantum yield of the fluorescent powder are improved by 5%-15%; after coating with theorganic coating layer, the luminous intensity reducing of the fluorescent powder is less than 3%; and the surface modification method provided by the invention has the advantages that the preparationtemperature is low, the time is short, the process is easy to control, and the surface modification method is suitable for industrial large-scale preparation.

Description

technical field [0001] The invention relates to the technical field of rare earth luminescent materials and lighting displays, in particular to a method for surface modification of fluoride luminescent materials and the prepared fluoride luminescent materials. Background technique [0002] As a new type of solid-state light source, white LED has the advantages of environmental protection, energy saving, high efficiency and fast response compared with traditional incandescent lamps and fluorescent lamps. The fourth generation of green light source after the light source. In the LED light source, the performance of the phosphor determines the technical indicators such as the luminous efficiency, color rendering index, color temperature and service life of the LED. Therefore, the phosphor plays a pivotal role in the white LED and has received widespread attention. At present, the most commonly used method is to combine the blue LED chip (luminous wavelength 440-480nm) with yel...

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Problems solved by technology

However, none of these methods overcomes the disadvantage that fluoride luminescent materials are easily hydrolyzed, and are easily hydrolyzed in long-term use or in humid environments, resulting in reduced luminous efficiency or even failure.

Patent document US2007 / 0125984A1 reports that a layer of inorganic material (such as TiO 2 、Al 2 o 3 , SiO 2 ) as a protective film to improve the moisture resistance of the phosphor; but this water-phase coating technology is difficult to apply to the coating of fluoride phosphors

Patent document CN106479485A also publicly reports that a layer of potassium silicate-hydroxymethylcellulose-polyethylene glycol mixture is coated on the surface of phosphor particles to improve the high-temperature and high-humidity resistance of phosphor powder; but this organic coating material, It also has the disadvantage of being not resistant to high temperature and easy to decompose, which affects the efficiency of long-term use of phosphors

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