Preparation method of yttrium aluminum garnet yellow fluorescent powder for white light LED

Abstract

The invention relates to a preparation method of yttrium aluminum garnet yellow fluorescent powder for white light LED (light-emitting diode). The method comprises the steps of: according to a stoichiometric ratio of each metallic element in Y3-x-yGdxAl5O12: yCe<3+>, preparing a mixed nitrate solution of metals contained in a target product; adding a soluble salt, an organic fuel and ammonium nitrate, heating the solution for dissolution till approximately a sticky state, conducting microwave irradiation so as to initiate self-propagating combustion; carrying out washing, drying, grinding andsieving, thus obtaining the yttrium aluminum garnet yellow fluorescent powder of a necessary particle size. The yttrium aluminum garnet yellow fluorescent powder prepared in the invention has controllable particle size, uniform size, regular appearance, and excellent light-emitting performance, and has the advantages of convenient implementation, simple equipment, short synthesis time, no need for long-time material mixing, high-temperature calcination, and ball-milling crushing. Therefore, the preparation method of the invention is a rapid and energy-saving new method for controlling the synthesis of yttrium aluminum garnet yellow fluorescent powder of different particle sizes.

Description

Technical field [0001] The invention belongs to the technical field of material preparation, and particularly relates to a method for preparing rare earth luminescent materials. Background technique [0002] Light-emitting diode LED (1ight-emitting diode) is a new type of solid-state lighting electric light source, which has the advantages of high efficiency, energy saving, green environmental protection, long life, small size, impact resistance, fast light-emitting response and low working voltage. And other fields have been widely used, and now white light LEDs have now begun to challenge the solid position of incandescent lamps and fluorescent lamps in the lighting field, and are expected to gradually replace them, thus presenting a huge market prospect. [0003] There are two main ways for white light LEDs to produce white light: the first is to combine red, green, and blue LEDs to produce white light; the second is to use LEDs to excite light and convert phosphors to mix to fo...

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Problems solved by technology

Adding flux related to the present invention to promote YAG:Ce 3+ The literature on phase formation and particle size control mainly includes: the Chinese invention patents whose authorized announcement numbers are CN1277901C and CN1318540C use chemical co-precipitation method or sol-gel method to control the preparation of small particle size precursors, and then add flux in solid form, It needs a certain mixing time, it is not easy to mix evenly, and the preparation process of the precursor is complicated and difficult to control

In 2007, Huang Yan also used the precipitation method to make the precursor, and then mixed the obtained precursor with a certain amount of inorganic salt to grind evenly, and then calcined at 1500°C for 2 hours to obtain a high-performance YAG product with a particle size of 3~5μm ; In 2010, Huan Jiao et al. used the sol-gel method to prepare the precursor, and then mixed the precursor with a certain amount of LiF. After grinding and mixing evenly, the phase could be formed at 700°C, but the luminescence was poor, and the sol-gel method It takes a long time and it is difficult to get industrial application (Powder Technology, 2010,198:229–232)

[0005] The existing solution combustion method uses the heat release of the redox reaction itself to complete the reaction. Once the reaction is initiated, no heat provided by the outside is needed. It is characterized by uniform mixing of component ions, fast reaction speed, and short time. The high temperature can be reached in an instant, but this method has the problems of serious particle sintering and agglomeration, large particles and irregular shape

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