Method for combining yellow fluorescent powder used for white light LED

Abstract

The invention provides a method for combining a yellow fluorescent powder used for a white light LED and belongs to the preparation technique of rare earth fluorescent powders. The chemical formula thereof is (Y1-x-yMyCex)3Al5O12, wherein M is one chosen from Tb, Gd, Sm and Yb, x is more than or equal to 0 but less than or equal to 0.1 and y is more than or equal to 0 but less than or equal to 0.1. The method comprises the following steps of: weighting yttrium salt, M salt, cerium salt, aluminum salt according to the element measurement and a defined amount of surface active agent and fluxing agent, fully mixing the reactants, the surface active agent and a defined amount of ligand, ball-milling while adding proper lubricant, filtering, washing and drying so as to acquire a precursor, mixing the precursor with the fluxing agent, and burning in a reducing atmosphere so as to acquire the needed fluorescent powder. The method for combining the fluorescent powder of the invention has the advantages of low burning temperature, short time, high production efficiency, small grain size, narrow distribution, excellent lighting performance and capable of being efficiently aroused by the blue light LED chip.

Description

1. Technical field [0001] The invention relates to a method for synthesizing luminescent materials, in particular to a method for synthesizing yellow fluorescent powder for white light LEDs. 2. Background technology [0002] Yttrium aluminum garnet (Y 3 Al 5 o 12 , YAG) is an important luminescent material matrix, which has the advantages of good mechanical strength, chemical stability, thermal conductivity, high quantum efficiency, small creep, strong high temperature oxidation resistance, etc., and can be applied to refractory and insulating materials. In the 1990s, Japan’s Nichia Corporation used blue LEDs to excite yellow phosphors (YAG: Ce) to combine blue and yellow light to obtain bright white light, and light-emitting diodes began to enter the lighting field. [0003] At present, there are many methods for preparing yttrium aluminum garnet phosphor, mainly including high-temperature solid-phase method, sol-gel method, precipitation method, combustion method, micro...

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Problems solved by technology

Patents of high-temperature solid-phase method such as: US 6614179B1, CN 1482208A, CN 101126024A, although the process is simple and the cost is low, but due to the high calcination temperature and long time, the particles are coarse, and the subsequent mechanical powder meter process will lead to the surface of the phosphor powder. The degree of crystallinity is severely damaged, causing a significant decline in luminous performance; sol-gel method patents such as: CN 1664063A, CN 101249978A, although the phosphor particles prepared are small, the process is complicated, the cost is high, toxic, polluting, and harmful to the human body Harmful; precipitation method patents such as: CN101113333A, CN 101012376A, although solve the shortcomings of the sol-gel method, but there are great difficulties in process control, it is difficult to guarantee the stability and consistency of the final product, and the synthetic product agglomeration is serious; burning Patents such as CN 1398817A, although the synthesis temperature is greatly reduced, the synthetic product particles are fine and evenly distributed, but the purity of the product is reduced, the luminescence performance is poor, and a large amount of gas is released during the preparation process; the microwave method patent is such as: CN1052745C, although the synthesis system can be used in a very short time Heating uniformly within a certain period of time, but depending on the substance being acted on, it is generally necessary to take certain measures for the raw material in order to effectively use the microwave; gas phase method patents such as: CN 1775904A, CN 1597841A, although the synthesized product particles have good dispersibility, small particle size, Narrow distribution, but low yield, hollow product particles, low luminous intensity and poor stability

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