A method for preparing silicon-aluminum nitride or nitrogen oxide phosphor

Abstract

The invention belongs to the technical field of fluorescent powder preparation, particularly relates to a method for freeze drying and auxiliary combustion synthesis of silicon-aluminum nitride or oxynitride fluorescent powder, and is characterized in that the method is implemented according to the following steps: (1) weighing raw material powder and a PVB binder according to the stoichiometric proportion of a fluorescent material; (2) adding the raw material powder and the binder to a tertiary butanol solvent, and carrying out ball milling, to obtain an evenly mixed slurry; (3) freezing and curing the obtained slurry for 2 h to 6 h; (4) placing the cured blank in a freezing dryer, carrying out vacuum drying to obtain a porous blank; and (5) placing the porous blank in a combustion synthesis reaction kettle, placing a Ti powder on the upper surface of the front end of the blank to be used as an igniting agent, vacuumizing, then filling nitrogen gas, and triggering the blank to carry out combustion synthesis reaction. The prepared silicon-aluminum nitride or oxynitride fluorescent powder has the advantages of uniform particle size distribution and good crystallization, allows the product to have no sintering agglomeration phenomenon, has no need for a subsequent crushing treatment process, and has significant advantages in preparation cost.

Description

technical field [0001] The invention belongs to the technical field of fluorescent powder preparation, and in particular relates to a method for synthesizing silicon-aluminum nitride or nitrogen oxide fluorescent powder with freeze-drying assisted combustion. Background technique [0002] Silicon-aluminum nitride or oxynitride phosphors have a very rich crystal structure. By changing the local crystal structure around the active ion, the energy level of the active ion can be split by crystal field, so as to obtain near-ultraviolet and blue light excitation and rich The emission spectrum, including red, green, yellow, and blue luminescence, has attracted great attention from the scientific and industrial circles. [0003] At present, the synthesis and preparation methods of silicon-aluminum nitride or nitrogen oxide phosphor mainly include high-temperature solid-state reaction method, gas phase reduction nitriding method, carbothermal reduction nitriding method, direct nitrid...

AI Technical Summary

Problems solved by technology

Chinese Patent Authorization Announcement No. CN101857441 B discloses a method for preparing b-silicon nitride powder. The method uses a foaming method to prepare a porous green body for combustion synthesis. It triggers the organic matter in the slurry by adding an initiator and catalyst. The monomer and the cross-linking agent undergo a cross-linking reaction to solidify the powder particles. After evaporating the solvent, a porous green body is obtained, while a large amount of high-molecular organic matter remains in the green body. This patent is through the generation of chain-like high-molecular organic matter To stabilize the porous structure, the inventors found that during the combustion synthesis process, a large amount of organic carbonization and evaporation will seriously affect the effective doping of rare earth ions in the synthesis process. In addition, the chemical reaction process is complicated, such as pH value adjustment, machine monomer, The control factors such as cross-linking agent, initiator, and catalyst solubility ratio are complex, so the operability, stability, and repeatability are low, and it is not suitable for industrial applications

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